3

MEXICO

1846–1848

The leaders of Mexico did not take kindly to the independence of Texas, made possible by Sam Houston’s victory over Santa Anna at San Jacinto in April 1836. Nor were they thrilled when, a few years later, talk of annexation with the United States began in earnest. Texas, Mexicans believed, was part of the great republic that stretched from the southern border of Oregon to present-day Guatemala. That Texas would merge with Mexico’s northern neighbor was unacceptable. Indeed, when the issue of annexation gained political momentum in Washington, Mexico considered itself at war with the United States.

War, however, was not inevitable. With the precedent set by the purchase of Louisiana, the United States several times had offered to buy Texas. These offers had been rebuffed, as had a special envoy, John Slidell, appointed by the American president, James K. Polk, to negotiate a peaceful resolution of the differences between Mexico and the United States.

Polk had been elected in 1844, the first dark horse candidate to win the White House. He was a partisan Democrat, a protégé of Andrew Jackson who honored his pledge to serve but one term. Most historians rate Polk’s presidency a success. He achieved a number of his goals, none more important than fulfilling his campaign pledge to bring Texas into the Union.

This accomplishment resulted in war with Mexico, a conflict his political opponents labeled “Polk’s War.” That he forcefully exercised his constitutional authority as commander in chief is indisputable. Polk was a focused chief executive, not reluctant to direct the nation’s military. When the United States Army and its sister service, the navy, completed their mission, the nation they served was considerably larger. Via Polk and the war with Mexico the United States acquired the territory that now comprises the states of Arizona, California, New Mexico, Nevada, Utah, and parts of Wyoming and Colorado. Thus the war was no mere footnote in American history.

As wars do, this three-year conflict caused much blood to flow. The Americans suffered well over twelve thousand deaths, the Mexicans far more. Of U.S. losses only some fifteen hundred were on the battlefield. The rest were the result of disease. In this regard the record of the 3rd U.S. Artillery Regiment is illustrative. The regiment had 224 men killed in the war. Yet only 41 were killed in battle. The others perished from various illnesses. Influenza, smallpox, dysentery, measles, yellow fever—even sunstroke—afflicted the soldiers in Mexico, often fatally.

The first Americans to die in the war were killed by Mexican soldiers who had crossed the Rio Grande into Texas. There, they ambushed an American patrol. Sixteen U.S. troops were killed or wounded. The Americans were part of a much larger force commanded by Brigadier General Zachary Taylor that had been ordered into Texas upon annexation. Its mission was to guard the new American lands and, should there be hostile action on the part of Mexico, to undertake offensive actions. With an army of nearly four thousand men Taylor had the means to do so.

He also had the inclination to fight. Taylor was a veteran commander, not given to pomp and protocol. His soldiers affectionately referred to him as “Old Rough and Ready.” He began his expedition into Mexico in the spring of 1846. When he finished, Taylor would be a national hero who soon would become president of the United States.

In late April, Taylor informed the authorities in Washington that hostilities had commenced. War fever in the United States was high, and President Polk had little difficulty in securing from Congress a declaration of war. He then called for fifty thousand volunteer soldiers who, in time, would expand the ranks of the army. Polk also ordered the navy to blockade Mexican ports. The United States was bent on teaching Mexico a lesson, and at least early on, most Americans were fully supportive of Polk and the war. Only a few Whigs, the country’s other political party, were against it.

Zachary Taylor, a Whig, was not one of them. He took his army inland and on May 8, 1846, confronted Mexican forces on flat land a few miles north of the Rio Grande, at a place called Palo Alto. At three o’clock in the afternoon, Mexican artillery opened fire, soon followed by cavalry charges. These were repulsed. Taylor’s men were army regulars, disciplined and skilled. Eventually, the gunfire ignited the grasses, and a large fire ensued, killing many of those wounded unable to move.

The next morning, the Mexican commander General Mariano Arista withdrew his troops a few miles south, to Resaca de la Palma. There, he held a strong defensive position. Taylor called a counsel of war, at which most of his officers urged waiting for reinforcements. As John S. D. Eisenhower wrote in his book on the Mexican War, that was not Taylor’s style. He ordered an attack that, after much hand-to-hand fighting, resulted in victory for the Americans.

In these two engagements Zachary Taylor reported 34 Americans killed and 113 wounded. Many more Mexicans were dead. Indeed, U.S. troops buried 200 of their foe. Among the surviving U.S. soldiers was a young lieutenant by the name of Ulysses S. Grant.

After his victories at Palo Alto and Resaca de la Palma, Taylor was promoted to the rank of major general, at the time the highest rank in the U.S. Army. Perhaps more significantly, his army received additional soldiers. However, these mostly were untested volunteers whose tour of duty was limited. Moreover, the increase in numbers was not matched by a corresponding increase in supplies. So his force, burdened by sickness and by the need to garrison those towns through which it had passed, was far from robust. Still, when he proceeded west toward Monterrey, Taylor had about six thousand men.

Monterrey (not to be confused with the California town Monterey) was the principal city of northeastern Mexico. With a population of approximately ten thousand inhabitants, it was the capital of the state of Nuevo León. Taylor’s army reached the city on September 19, 1846. The Mexicans were there in strength, led by General Pedro de Ampudia, who, like Arista, was an experienced commander. Though outnumbered, Taylor chose to attack. He divided his forces (a tactic not always advisable) and came at Ampudia from opposite ends of the town. The battle lasted three days. Toward the end, the Americans were advancing not through the streets, but literally through the walls of the houses lining the streets. This was the first time the U.S. Army had to fight house to house. On September 24, with the Americans in possession of the city, Ampudia sought terms of surrender. Taylor appointed several of his officers to conduct the negotiations. One of them, a Colonel Jefferson Davis, had commanded the Mississippi Rifles, a regiment that had fought particularly well. Terms were agreed to, and the guns, both American and Mexican, went silent. Polk thought the terms too lenient and was angry with Taylor, but nonetheless, Zachary Taylor had won another battle.

Since gaining independence from Spain in 1821, Mexico had had its share of charismatic leaders, none more colorful than Antonio López de Santa Anna. To the Americans he was the cruel victor of the Alamo who received his just reward at San Jacinto. To his fellow Mexicans he was, intermittently, el Presidente, army commander, patriot, and rogue. In 1845 Santa Anna had been exiled to Havana, his career supposedly over. But with Mexico in political turmoil, he returned the next year courtesy of the U.S. Navy, which, under specific instructions from Polk, allowed him to slip through the blockade. The American president hoped that with a new leader in Mexico, he might be able to negotiate an end to hostilities.

Polk was to be disappointed. With his customary zeal, Santa Anna raised an army. Then, on January 27, 1847, with much fanfare, he and his troops headed north. Their goal was to defeat Zachary Taylor in battle and rid their beloved country of the Yankee invaders. With twenty thousand men under arms—the largest force Mexico would assemble during the war—this goal was well within reach. The two armies met three miles south of the town of Saltillo, in a narrow mountain valley near the hacienda Buena Vista.

Taylor’s force, much reduced in effectiveness after Monterrey and, as always, hampered by large numbers of sick and dying, numbered 4,759 men, many of whom had not yet seen battle. At first wishing to attack, Taylor was swayed by one of his senior subordinates, Brigadier John E. Wool, to position his troops defensively at a spot within the valley known as La Angostura (The Narrows). It was a sound move.

Santa Anna arrived in the valley with fifteen thousand men, having lost a quarter of his army from desertion and disease in the march north. Still, he outnumbered Taylor three to one. And his troops were not lacking courage.

On the morning of February 22, 1847, Santa Anna sent a note to Taylor calling on the American to surrender. Old Rough and Ready declined to do so. The next day the Mexicans attacked in force.

The attack was spearheaded by both infantry and the famed Mexican lancers supported by artillery. Taylor’s regiments fought hard, stood fast, then on the left flank gave way. General Wool thought the battle lost. Not so Zachary Taylor, who realigned his troops and told Jefferson Davis to shore up the crumbling American line. Davis did so. The U.S. infantry held and, importantly, American artillery began decimating the advancing Mexicans. But Santa Anna did not give up. Again and again, he had his troops attack. The Illinois and Kentucky regiments were in the thick of it. Once again Taylor’s cannons found their target and the Mexicans withdrew. On both sides casualties were high. Taylor had 456 wounded and 267 killed. Among the latter was Henry Clay Jr., whose father had opposed the war in the presidential campaign of 1844.

The next morning Taylor and his men waited for Santa Anna to renew the battle. They waited in vain. The Mexican commander and his men had departed. Beaten, Santa Anna had taken his now much depleted army south. There he would raise more troops and defend his country and its capital from a new threat: General Winfield Scott and the nearly twelve thousand Americans who had landed at Vera Cruz.

Scott was the American army’s most senior general. An extremely able field commander, he was in addition a fine military administrator and meticulous planner. He also was politically ambitious, a Whig and therefore no favorite of Polk. In fact, the president cared little for either Taylor or Scott, concluding that both were unfit for high command.

Polk had hoped that Taylor’s expedition into northeastern Mexico would be sufficient to bring the Mexicans to the bargaining table. When that proved not to be the case, he realized that only if the Americans occupied the Mexican capital would the Mexican government sue for peace. Indeed, any attempt early in the war to negotiate with the United States was seen as treason by Mexico’s military and political elites.

So James Polk asked Winfield Scott for a plan to seize Mexico City, which the general duly produced. Once the plan was agreed to, the only question was who would be in charge. Reluctantly, Polk appointed Scott. In truth, he was the logical choice. No other American officer was his equal in stature or skill.

But Winfield Scott was not the only army officer Polk placed in command of an important expedition. On the day the United States declared war on Mexico the president, through Secretary of War William Marcy, directed Colonel Stephen W. Kearny to march west from Kansas to Santa Fe and take control of the lands comprising New Mexico. Once that was accomplished, he was to continue on to California. There, he was to help secure the Pacific territories for the United States.

With 1600 men Kearny departed Fort Leavenworth in June 1846. He had with him also 460 horses, 3,700 mules, 15,000 cattle and oxen, and 16 pieces of artillery. His force was hailed the “Army of the West,” and as it trekked through the desert, threats arose from hostile Indians, Mexican patrols, rattlesnakes, and dehydration. But, in mid-August, the colonel and most of his troops arrived in Santa Fe.

Kearny lost no time in establishing an American presence. He claimed the lands for the United States, promised U.S. citizenship to the inhabitants, drafted a constitution for the territory, proclaimed religious freedom, appointed civilian officials, and, along with his soldiers, tasted new foods that were then and now staples of the Southwest. Kearny’s energy seemed inexhaustible. Upon determining that all was in order, he moved on. With a much reduced force Kearny entered what is now the state of California on November 25. He had accomplished much, and Polk, in August, had rewarded him with promotion to brigadier general.

Unfortunately, back in New Mexico, the situation deteriorated. The soldiers left behind were behaving badly. Civilians still loyal to Mexico were plotting revenge. And, with a breakdown of law and order, common criminals felt unrestrained. The result was an outbreak of violence, at times brutal. Eventually, American troops pacified the territory, but not before well over two hundred people were dead.

When Kearny reached California, the towns and countryside were far from peaceful. Acting on orders from Polk transmitted via Secretary of the Navy George Bancroft, the American navy had occupied towns along the coast. But in addition to sailors and marines, U.S. Army soldiers had been deployed to California. Some of these were under the command of Lieutenant John C. Fremont, one of those figures in American history who appear larger than life.

Among the inhabitants of California, loyalties were mixed. Some folks wanted the territory to remain part of Mexico. Others favored a semiautonomous region within the southern republic. A few thought California should be an independent nation. Some just wanted to be left alone. A large number thought the future lay with the United States. After a fair amount of bloodshed, political intrigue, and squabbles between Kearny, Fremont, and the senior naval commander, Robert F. Stockton, that brought credit to none of them, the issue was decided. California would join the Union, which it did in 1850, becoming the thirty-first state.

As Kearny was moving into California, one of his officers who had remained in Santa Fe took his troops far to the south, eventually linking up with Zachary Taylor in Monterrey. The officer was Colonel Alexander Doniphan. He commanded about a thousand mounted Missouri volunteers. Besides the extreme hardship of the journey itself, Doniphan encountered elements of the Mexican Army, defeating them twice. When the Americans returned home to the United States, their epic march was over. Doniphan and his men were greeted as heroes.

Doniphan had reached Taylor’s camp early in May 1847. Two months earlier Winfield Scott had landed his army on the coast of Mexico, just south of Vera Cruz.

Well fortified and garrisoned by more than four thousand soldiers, Vera Cruz was the gateway to Mexico City, Scott’s ultimate objective. His troops came ashore on March 9, 1847. The landing was the first amphibious operation conducted by the United States military. By selecting beaches to the south of the city, Scott’s army of twelve thousand men met no opposition during the vulnerable transition from sea to land. The success of the endeavor spoke well of the planning Scott and his staff had conducted and of the skill of the American navy.

Purposefully, Scott eschewed a formal assault upon Vera Cruz. Instead, he brought heavy guns ashore and laid siege, opening fire on March 23. His artillery pounded the city continuously for seven days. Blockaded seaward by ships of the United States Navy and on land by soldiers of the U.S. Army, the Mexican troops in Vera Cruz had no hope of success. They soon surrendered, on March 29. Only 19 Americans had been killed. Their opponents lost approximately 180, many of them civilians.

Scott lost no time in departing Vera Cruz, heading west to the Mexican capital. He was anxious to avoid the onset of yellow fever, which on the hot and humid coastal plain was always present and often deadly. A small number of troops were left in the city. Throughout the remainder of the war, Vera Cruz would remain the port of entry for American reinforcements and supplies.

To reach Mexico City, Scott chose to march along the route taken by Cortés in 1519. This would take his army through the town of Cerro Gordo. There, Santa Anna, now president of the republic, as well as commander in chief of the army, had deployed some twelve thousand men in a strong defensive position. To his right were steep cliffs overlooking a river. To his left were high hills. The road to the capital ran through the hills. Conditions favored the Mexicans. Scott had but eighty-five hundred men and would be attacking troops well positioned and well armed.

The American commander organized a multipronged assault, one thrust of which was to strike at Santa Anna’s rear. This strike was made possible by daring reconnaissance conducted by an army engineering officer who somehow found a path around the Mexican left flank. The officer’s name was Robert E. Lee. The attack took place on April 18, 1847, and well before noon, the battle was over. Scott’s forces crushed those of Santa Anna. Sixty-three Americans were killed and 337 wounded. The number of Mexican casualties is uncertain, although it was no doubt large. More than 1,000 Mexican soldiers were captured, among them 5 generals. Santa Anna himself escaped, but the wagon carrying coin for his soldiers did not.

At Cerro Cordo Winfield Scott had won a great victory. But his objective was to occupy Mexico City, so he continued west, reaching the city of Puebla on May 28. With a population of seventy-five thousand, the town was among the most important in Mexico. At Puebla the Americans were two-thirds of the way to the capital. Their army numbered about six thousand, although many of these soldiers were in the hospital, unfit for combat. With volunteer brigades leaving for home, with the requirement to garrison towns along the way, and with the constant presence of men too sick to fight, the size of Scott’s army fluctuated even as reinforcements arrived from Vera Cruz two hundred miles away. Among the reinforcements to reach Puebla were twenty-four hundred regulars commanded by a brigadier general, Franklin Pierce. He and his troops joined up with Scott on August 6.

The next day the Americans broke camp. To hold Puebla, Scott left behind four hundred soldiers. With them were medical personnel attending eighteen hundred men. According to U.S. Army records the troops Winfield Scott took out of the city numbered 10,738. Their goal was to march about a hundred miles through enemy territory, attack a fortified city with a population of two hundred thousand people, and defeat in battle an army three times their size. In Great Britain the duke of Wellington, no stranger to military campaigning, is said to have deemed Scott’s position hopeless.

Accompanying Scott and his army was an American diplomat. With the capture of Vera Cruz Polk and Secretary of State James Buchanan thought the Mexican government might be amenable to discussing an end to the conflict. So they appointed Nicholas P. Trist to find out. Trist was the chief clerk of the Department of State, a lowly sounding title perhaps, but in reality the second-ranking official in the American Foreign Ministry. His résumé was impressive: Trist had studied law under Thomas Jefferson, had served as Andrew Jackson’s private secretary, and had been U.S. consul in Havana.

The capital of the Republic of Mexico was situated just west of three large lakes. To the north was Lake Texcoco, largest of the three. To the south lay Lake Chalco. Between them were extensive marshlands. The third lake was to the northwest of Lake Chalco and called Lake Xochimilco. To the west of this lake was El Pedregal, a stony hard lava field difficult to transit. The simplest way into the city was over causeways that crossed the marshes. However, easy to defend, these would be difficult if not disastrous for any attacking force to utilize.

On the advice of his engineers, among them not just Lee but a George B. McClellan, Scott chose to attack from the south, skirting around Lake Chalco and moving northwest, with Lake Xochimilco on his right. On August 17, his troops occupied the town of San Augustin, just nine miles from Mexico City.

Not unreasonably, Santa Anna had expected Scott to approach from the north. When he learned of the Americans’ movements, he redeployed his forces, moving General Gabriel Valencia’s army to meet the threat from the south. With four thousand troops Valencia moved into a position between two villages, Padierna and Contreras. He expected El Pedregal to complicate the expected American attack. It did, but it did not prevent it. Elements of Scott’s army crossed the lava field and defeated Valencia’s force. Santa Anna was not pleased. He ordered that Valencia, who had disobeyed an order to withdraw, be shot. Yet Santa Anna could have done better himself. At one time during the battle the Americans were vulnerable to a strike by the Mexican commander in chief’s men, who were positioned just north of Valencia’s. But Santa Anna stayed put. He thus missed an opportunity to inflict a decisive blow against Winfield Scott.

The battle was fought on August 20 and was over by noon. It was a stunning victory for the Americans. They killed some seven hundred of the enemy and captured more than eight hundred. Additionally, they took possession of substantial numbers of guns, mules, and other military supplies. As one scholar of the war, Robert Selph Henry, put it, Valencia’s army “had ceased to exist as a military unit.”

But Padierna, or Contreras as it is sometimes called, was only the first of two battles fought that day. The second would be far bloodier.

North of Pedregal was a small river, the Churubusco. The Mexicans had established a strongpoint at one of its bridges and at the Convent of San Mateo nearby. At both locations, Mexican artillery was in place, manned by Irishmen who had deserted from the American army. Known as the San Patricios, these men would fight hard, aware of the consequences should they be captured.

That afternoon the Americans attacked. In three separate actions, Scott’s army frontally assaulted the bridge and the convent. The army also struck at Mexican forces north of the river, crossing another bridge to the west that was undefended. Winfield Scott committed everything he had to this fight. At first the attacks were repulsed. Yet the Americans kept coming, with the bayonet often the weapon of choice. In time, despite fighting hard, the Mexicans gave way. Scott’s army had triumphed again.

But the cost to the Americans was high. The battles of August 20, 1847, had resulted in 1,016 casualties, most of them at Churubusco. The dead numbered 138.

For the Mexicans the day—it was a Friday—was a disaster. Santa Anna’s army had been crushed. Four thousand Mexican soldiers were killed or wounded. Three thousand were taken prisoner. Santa Anna and the remnants of his force withdrew to the outskirts of the capital city itself. There they waited, expecting the American commander to regroup and attack again.

Instead, Scott proposed a truce.

He reasoned that it might encourage the Mexican government to discuss how to end the war, a view concurred with by Nicholas Trist. Moreover, further bloodshed would be avoided and the needs of the army better served. Scott’s healthy soldiers needed to rest. His wounded needed attention. Both were in need of supplies, particularly food. So the general offered a cease fire, knowing that, if need be, his army could easily engage the enemy once again.

The Mexicans accepted Scott’s offer. On August 20, the two sides signed an armistice. The agreement called for a cessation of hostilities and an exchange of prisoners. It forbade military reinforcements and permitted the Americans to secure supplies from within Mexico City.

Scott hoped that with the guns silent, Trist would be able to negotiate a peace treaty. But the diplomat was unable to do so. The Mexicans were not yet ready and the American terms were too stiff. Meanwhile, Santa Anna, a genius of sorts but not an individual to be trusted, had begun rebuilding his army (a task for which he showed extraordinary aptitude) and enhancing Mexican defenses, two activities expressively forbidden by the agreement. Whether the Mexican general ordered that supplies to the Americans be limited is unclear, but they were not as easily obtained as Scott had hoped. On September 6, 1847, the American commander notified his counterpart that the truce was no longer in force.

Two days later American artillery opened fire, in support of infantry that was marching into battle. Their targets were two stone buildings situated outside the capital city. These were known as Molina del Rey and Casa Mata. The former was a foundry Scott believed to be manufacturing cannons. The American force was no small detachment. In total it numbered 3,250 men. One of them, Captain Kirby Smith, wrote his wife the night before that “tomorrow will be a day of slaughter.”

It was. The Mexican defenders were well deployed and, as they so often did, fought tenaciously. As the Americans surged forward, General Peña y Barragán organized two counterattacks. These failed, and after hard fighting, Scott’s forces, led by Brigadier General William Worth (who, after the war, would give his name to a fort in Texas near the future city of Dallas), carried the day. Worth’s men suffered terribly: 653 were wounded, 117 were killed, in total nearly one-fourth of the attacking force. Those who survived, and Kirby Smith was not one of them, were ordered to return to their base. General Scott had envisioned the attack as a raid, not as an assault to win and hold ground. Later, both American commanders learned that no capability to construct cannons existed at the Molina.

The next target for American artillery was the fortified, rocky ridge called Chapultepec. Two hundred feet high, it dominated the landscape. At its top were several buildings that once had served as the summer palace of the Spanish viceroys. In 1847 they constituted the Mexican military college where young cadets learned the art and science of warfare. Chapultepec was significant, not as a military objective, but as the very symbol of the Mexican Republic. To capture it would signal an American victory. To lose it to the invaders would mean Mexican defeat and dishonor.

The battle for Chapultepec was to be the climax of the war.

On September 12 the American bombardment began. It lasted fourteen hours. The Mexican commander on the ridge, Nicolás Bravo, a hero of the effort in 1821 to oust Spain, called for reinforcements. Santa Anna, believing Chapultepec to be vulnerable, denied the request. He preferred to save his rebuilt army for a last-ditch defense of the city itself.

Scott carefully planned his attack. He feinted an assault from one direction and struck from two others. His troops stormed up the muddy slopes. Fighting was fierce, often hand-to-hand. More than once quarter was neither sought nor given. One American lieutenant, James Longstreet, fell wounded. The flag he was carrying was picked up by a fellow officer, George Pickett. The Mexicans fought hard. But the Americans kept coming. They were unstoppable. Two hours after it began, the assault was over. Scott’s army controlled Chapultepec, at a cost of 834 casualties.

Mexico had lost the battle, and the war. But it had gained a legend. The cadets of Chapultepec had fought the Americans and died for their country. Their heroism would never be forgotten. Today, as in the past, los niños héroes de Chapultepec are celebrated throughout the Republic.

The Americans also gained something memorable. Among the troops assaulting Chapultepec were forty United States marines. Fighting hard, they had reached the top of the ridge, entering what the hymn of their beloved corps would term “the halls of Montezuma.”

The bloodshed did not stop with the American capture of Chapultepec. Scott’s army pushed on, entering Mexico City. There, as at Monterrey, men fought house by house, street by street. Destructive and bloody it was, but the battle was over by the end of the day. The Americans controlled the capital of Mexico.

Instead of a last-ditch defense of the city, Santa Anna chose to leave. Within the city and at Chapultepec he had lost some eighteen hundred men. Seeing no hope of winning, he and a still substantial number of men evacuated the city. Santa Anna hoped there would be another battle, one that he might win and so turn the tide. No such battle would occur. A few skirmishes perhaps, but no further engagements wherein armies clashed. The Mexican War was over. The United States had won, and decisively so.

Winfield Scott entered Mexico City on September 14, 1847. He had accomplished what he had set out to do. He had taken Vera Cruz, defeated the Mexicans at Cerro Gordo and Contreras, won victories at Churubusco and Chapultepec, and captured the Mexican capital, all in seven months. And he had done so with a relatively small army. Scott had done what a senior commander must do: he had planned, organized, and directed. Others would do the actual fighting. Winfield Scott had performed brilliantly. That few Americans remember him today detracts not at all from his accomplishment.

With Santa Anna gone, the civic leaders of Mexico City met with Scott. Together they arranged the American occupation of the capital. This would last until June of the following year, and was relatively peaceful. Scott himself departed in February.

Once the fighting essentially was over, Nicholas Trist entered center stage. His job was to negotiate a peace treaty. In doing so, he faced several obstacles, two of which were substantial. The first was that the Mexican government was far from organized. Securing legitimacy for discussions with the Americans was difficult, much less agreeing on terms. The second obstacle was more straightforward. Trist was recalled by Polk. The president thought that the emissary’s long stay in Mexico conveyed the message that the United States would do practically anything to nail down a treaty. Polk, through Buchanan, ordered Trist home.

Nicholas Trist then did something extraordinary. He ignored Polk’s directive. Trist reasoned that the best chance for successful negotiations lay with him already there and at work. So he stayed put. In time, the Mexicans came to the table and they and Trist produced a settlement. It is called the Treaty of Guadalupe Hidalgo after the town in which it was signed.

The treaty established the boundary between Mexico and its northern neighbor. Additionally, the agreement called for the latter to pay the former $15 million for the lands ceded to the United States and to assume payment of certain claims filed against Mexico. Not surprisingly, as Trist had negotiated from a position of strength, terms of the treaty were favorable to the United States. As for the Mexicans, they just wanted the Americans to leave.

Angry with Trist, Polk nonetheless submitted the treaty to the U.S. Senate. Approval was not a foregone conclusion. Some senators wanted even more territory, some less. Some wanted slavery prohibited in the lands gained. To this, senators from the South predictably objected. Some simply wanted to embarrass Polk, as he and “his war” no longer were popular.

Debate in the Senate lasted eleven days, during which there were thirteen roll call votes. Finally, on March 10, 1848, the treaty, in modified form, was brought to a vote. It passed thirty-nine to fourteen. The Mexican Chamber of Deputies and Senate agreed to the same text in May.

On June 19, 1848, amid great fanfare, the Stars and Stripes were hauled down in the center of Mexico City. Replacing the American flag was the green, white, and red banner of the Republic of Mexico. Control of the city, and therefore of the country, reverted to those to whom it belonged.

Why did Mexico not win?

Throughout the conflict Mexico enjoyed several advantages that might have led to victory: On the battlefield the Mexicans usually outnumbered the Americans. They were well armed and not lacking in courage. Indeed, Mexican troops fought hard and with skill. Moreover, they were defending their homeland, a situation that often serves to motivate soldiers. So why did they not defeat the Americans? The answer lies in the skill of their military commanders. The Mexican generals, particularly Antonio López de Santa Anna, were not up to the tasks entrusted to them. They failed the test of leadership.

Why did the Americans win?

The Americans won their war with Mexico because the United States Army performed superbly. At the top were two generals who were expert at their trade. Zachary Taylor both inspired his men and positioned them to win. Winfield Scott organized and led an expedition into the heart of enemy territory and did so brilliantly. In the middle were the lieutenants and captains, many of them graduates of the newly established military academy adjacent to the Hudson River. At West Point these young officers learned skills that served them well at Monterrey and Buena Vista, Cerro Gordo and Chapultepec. Many of these officers—Grant, Longstreet, Lee, and Meade among them—would be heard from again. At the bottom ranks of the U.S. Army were the ordinary soldiers. They were regulars and volunteers, two distinct groups that rarely held the other in high regard. But in battle, each fought tenaciously, matching the courage of their Mexican counterparts.

In support of these officers and men was a branch of the army that deserves special mention. Throughout the war, American artillery was particularly effective, often, as John S. D. Eisenhower has written, “the difference between defeat and victory.”

Was the war with Mexico a just war?

The Whigs certainly thought not. Fourteen Whigs had opposed the initial declaration and, as the war continued and casualties mounted, opposition to the war increased. In the 1846 midterm elections Polk’s Democrats lost control of the House of Representatives, largely due to the war. Two years later they lost the White House. Whigs saw the war with Mexico as a blatant grab for land or simply as a partisan ploy on the part of Polk. They also saw the war as an effort by Southerners to extend slavery. Subscribing to the last view was a veteran of the conflict and of the one that followed. In his memoirs, Grant wrote that the Mexican War was unjust and, moreover, that the annexation of Texas itself was a conspiracy to bring additional slave states into the Union.

If Grant was correct, then the war clearly was not justified. But there is another interpretation, one that sees the war as not about slavery, but about land. Many Americans, Whigs, and Democrats alike believed that the United States should extend to the Pacific coast. They considered it America’s destiny to span the continent. The war to them was simply the means by which destiny was to be realized.

Was the war then simply an effort to acquire land?

If so, and this view has much merit, was the effort an honorable one? Some would say no. They would contend that the United States invaded Mexico and, by force of arms, stripped it of land. Others would see a more complicated picture. They would point out that the land in question was sparsely inhabited, that many of the inhabitants had no love of or allegiance to the Republic of Mexico, and that in the Treaty of Guadalupe Hidalgo the Americans paid Mexico for the land ceded to the United States.

Justified or not, was the war inevitable?

One purpose of diplomacy is to settle differences between nations without either side resorting to force. In the case of Mexico and the United States in the 1840s, diplomacy failed. James Polk tried to negotiate with Mexico but was unable to do so. Once Texas became part of the Union, Mexico considered itself at war. To keep the peace, diplomacy would have had to accommodate Mexican pride and grievances and, at the same time, take into account America’s irresistible appetite for new lands. That was not impossible, but only a saint could have brokered a peaceful resolution. None was available in 1846.

Did the Mexican War have a significant impact on the United States?

It most certainly did. The conflict of 1846–1848 shaped the future of the country. Most importantly, and obviously, the war increased the nation’s size. The territory that now comprises the states of Arizona, California, Nevada, New Mexico, and Utah as well as parts of Colorado and Wyoming became part of the United States. The dream of many Americans for a nation that stretched from the Atlantic to the Pacific became a reality.

America’s military greatly benefitted from the war. Those young West Pointers who served under Zachary Taylor and Winfield Scott gained experience in Mexico. When they rose to command Union and Confederate armies in 1860–1865 they were battle-tested. Historian Douglas V. Meed reports that more than 130 men who saw service in the Mexican War achieved the role of general in the armies of either the North or the South.

The American Civil War began as an effort to preserve the Union. Abolitionists in the North may have wanted to abolish slavery in 1860, but Abraham Lincoln didn’t. He wanted to keep the United States together. Had slavery been limited to those states where it had an established foothold, the war might not have been fought. But the expansion of the United States in 1848 —resulting from the war with Mexico—raised the question of whether the new lands would be free or slave. That caused slavery to be an issue on the national agenda, one that could not be set aside. Extremely contentious, the failure to resolve the issue triggered events that twelve years after the conclusion of the war with Mexico led to Americans again taking up arms, this time against one another.