Chapter 10

To the Halls of Montezuma: Fighting Mexico

In This Chapter

Clashing with Mexico over expansion

Fighting in Texas and northern Mexico

Snatching California

Invading the heart of Mexico

As the 1840s began, the United States was growing by leaps and bounds. This hustling, bustling growth was embodied in one word: expansion. Many Americans envisioned a future in which their country would stretch from coast to coast, comprising an “empire of liberty.” They believed in the notion of Manifest Destiny — the idea that God had bequeathed much of the North American continent for the United States so it could spread its unique culture, liberty, and wealth from the Atlantic to the Pacific, in the process bettering humankind.

Behind the veneer of this idealism, expansion was really motivated by economic interests. The territory west of the Mississippi River contained good farmland, resources, waterways, and places to build railroads, and the glistening Pacific Coast beckoned as well. Americans dreamed of going west to find wealth, security, and personal independence. As the 1840s unfolded, more and more Americans were migrating west, pursuing their dreams. Inevitably, this led to tension with Mexico, another new nation intent on expansion as well. The ultimate, and sad, result of this tension was war between the two countries.

In this chapter, I explain the key events that led to the Mexican-American War, including the underlying causes of the conflict. I show how diplomacy failed and shooting began. I describe the amazing string of American military victories, explain why they happened, and relate the war’s most important consequences.

Clashing Over Expansion

Mexico won its independence from Spain in 1821. In so doing, the new nation inherited much of the sparsely populated, loosely controlled Spanish empire in North America. This empire encompassed the entire west coast and about half of the land west of the Mississippi River, stretching all the way to the Canadian border. Mexico could not hope to control this huge swath of territory, especially when Americans began to migrate westward.

Like the Americans, Mexican settlers had difficulty with Native American tribes (see Chapters 6 through 9). Very few Mexican settlers ventured farther north than present-day California or Texas. In fact, much of northern Mexico was so lightly populated that the Mexican government actually encouraged Americans to settle in such places as Texas (the Spanish government had once done the same thing throughout its North American empire). Eventually, as youthful Mexico and the United States grew and attempted to expand their power over the continent, the two clashed.

The Republic of Texas emerges

Throughout the 1820s and 1830s, American settlers, with the blessing of the Mexican government, migrated to Texas which, at that time, was part of Mexico. The Americans helped stabilize Texas and make it prosperous. They subdued Native American tribes, cultivated farms, and built seaports. They also coexisted peacefully with Spanish-speaking Mexicans. Culturally, the Americans were different, though. They spoke English, worshipped in Protestant churches, and believed strongly that governments should not interfere with individual liberties. Also, most of them were southerners who favored slavery, so they were aghast when, in 1829, the Mexican government abolished slavery.

In the mid-1830s, the Mexican government, under Gen. Santa Anna, sought to centralize power throughout Mexico’s northern states. Nearly all these states, including Texas, rebelled against this new supervision. In 1836, Texas fought for and won its independence from Mexico. The United States, Britain, and several other nations recognized the independence of the Texas republic, but Mexico would not do so. The Mexican government never accepted the loss of Texas and considered it a breakaway, rebellious province.

By the early 1840s, the people of Texas wanted the United States to annex their state. Many Americans wanted to welcome Texas into the Union, but this action presented two problems:

The Mexican government would view Texas’s addition to the United States as an act of war because it still believed Texas belonged to Mexico.

In the United States, northerners and southerners were divided over slavery, which was legal in the South but not the North. Many northerners didn’t want Texas because it would come into the Union as a slave state.

At that time, Texas was larger than the state we know today. The Texas of the 1840s consisted of land that would someday comprise parts of Oklahoma, New Mexico, Colorado, Kansas, and even Wyoming.

Polk’s plan to expand

The question of Texas annexation, and expansion in general, was the main issue of the 1844 U.S. presidential election. James K. Polk, the Democratic nominee, was a pro-expansion Tennessean. Believing in Manifest Destiny, Polk wanted to expand America’s control all the way to the Pacific Ocean. His expansion plans called for

The annexation of Texas, which southerners wanted

The acquisition from Britain of the Oregon territory in the Pacific Northwest, which northerners liked because slavery wouldn’t be legal there

These ideas were popular enough to propel Polk into the White House. Upon taking office in 1845, he immediately went about fulfilling his promises to expand the United States all the way to the Pacific Coast.

Annexing Texas and flirting with war

On March 1, 1845, the U.S. government passed a bill annexing Texas. The Texans eagerly agreed to the annexation, as well as a pro-slavery state constitution. On December 29, 1845, Texas officially became part of the United States.

Mexico considered the annexation to be an act of war. The Mexicans, who had never recognized the legitimacy of Texas independence, argued that the state still belonged to them (see the earlier section, “The Republic of Texas emerges”). Thus, the Mexicans believed that the United States had stolen their land. War fever swept through Mexico. So did political chaos. In 1846 alone, the Mexican presidency changed hands four times. Only politicians who favored war with the U.S. could hope to remain in power.

Americans, by contrast, were divided on the prospect of war. Most southerners were for war because they favored Texas’s entry into the Union and believed that Polk’s expansion policy would someday produce more slave states. Northerners, especially in the opposition Whig party, tended to oppose the idea of war, mostly because they felt that war would favor southern slave owners.

Trying diplomacy, then baiting for war

In the winter of 1845–1846, Mexico and the United States were close to war. President Polk, committed though he was to expansion, much preferred to achieve his goals through diplomacy rather than war. He sent an emissary, John Slidell, to Mexico City in hopes of defusing the Texas flap and negotiating a purchase of the California and New Mexico territories. Polk authorized Slidell to offer as much as $30 million for this land; Slidell also could forgive $4.5 million in Mexican debts to the U.S.

So hawkish (war-minded) was public opinion in Mexico, that when President José Joaquín de Herrera even considered meeting with Slidell, he fell from power. A military, pro-war government replaced Herrera’s. The leaders of this new government refused to meet with Slidell. They considered his mere presence in Mexico to be an insult. Thus rebuffed, Slidell left the country and advised Polk that war was the only option.

Polk sent an army of 4,000 soldiers under Gen. Zachary Taylor to south Texas. Ostensibly, they were there to keep an eye on the Mexicans, but most likely, Polk was using them as bait to goad the Mexicans into attacking them. The Americans believed the border with Mexico was the Rio Grande, a river that flows out of the Rocky Mountains to the Gulf of Mexico. The Mexicans thought the border was at the Nueces River, 100 miles to the north of the Rio Grande. When Polk ordered Taylor to move south of the Nueces, toward Corpus Christi, the Mexicans attacked him on April 25, 1846, killing 11 Americans, giving Polk an excuse for war. Actually, by the time of this skirmish, Mexico had already declared a state of “defensive war” with the U.S.

When Polk heard this news, he asked Congress for a declaration of war. The president stated that Mexico had “invaded our territory and shed American blood upon American soil.” On May 13, Congress voted for war.

Interestingly enough, one of those who voted against the war was a young Whig congressman from Illinois named Abraham Lincoln. The future president opposed the war because he thought it was nothing more than an immoral land grab to spread slavery.

Favoring the eventual loser

Believe it or not, most European and Mexican military leaders believed that Mexico would win this war quite easily. The Mexican army was nearly four times the size of the U.S. Army, with many professionally trained officers. The Mexicans would be fighting on their own turf, with plenty of food, ammunition, and popular support. Europeans had very little respect for American military prowess. They thought that the Americans wouldn’t be able to supply their troops in the far-flung Southwest. Nor, they thought, did they have the maturity to subdue a Mexican fighting force so much larger than their own.

These were shortsighted views. The Americans were indeed outnumbered, but they had better weapons, better training, better military leaders, better soldiers, and a stronger national economy to support them. The U.S. also had a good navy, something the Mexicans lacked.

“Old Rough and Ready” Taylor

The Mexican-American War made Zachary Taylor a household name and national hero. Born in 1784 to a Virginia plantation family, he was the third of nine children. When he was young, the family moved to Kentucky. In 1808, he decided to join the Army. Using his family’s social connections, he secured a first lieutenant’s commission in the 7th Infantry Regiment.

For the next 38 years, Taylor fought in several wars and served in a variety of military posts. He was a strict but fair officer with a wry sense of humor. For instance, one day he caught a rowdy soldier using a coffeepot to smuggle whiskey into camp. Taylor ordered the soldier, Private Charles Gray, to wear the coffeepot on his uniform for the next month. “I had been made a soberer, a wiser, and a better man,” Gray later said.

Taylor was promoted to general in 1838. Earning for himself the nickname “Old Rough and Ready” for his rumpled clothing and trademark straw hat, Taylor won several battles against the Mexicans in 1846–1847. These victories propelled him into the national spotlight. With his popularity on the rise, the Whig party recruited him as its presidential candidate in 1848. He won the presidency but died in office on July 9, 1850.

Gen. Zachary Taylor’s Campaign

In the wake of the opening skirmishes with the Mexican army along the Rio Grande, Gen. Zachary Taylor had acute supply problems. Most of his army was in and around Fort Brown, on the river, near the location of present-day Brownsville, Texas. In early May, Taylor left a force of about 600 soldiers at the fort while the rest of his army backtracked to Point Isabel, his main supply port, 28 miles to the northeast, on the Gulf of Mexico (see Figure 10-1). In doing this, Taylor hoped to replenish his army and establish a strong supply line from Point Isabel to Fort Brown. His decision set in motion a series of battles that ultimately led his army into northern Mexico.

Figure 10-1: Map of the Mexican-American War.

Battles at Palo Alto and Resaca de la Palma

As Taylor’s column made its way to Point Isabel, a 6,000-man Mexican army under Gen. Mariano Arista shadowed them. On May 8, 1846, the two forces fought a sharp engagement at Palo Alto.

The fighting raged over the course of four desperate hours. The outnumbered Americans held off several enemy charges, partially because of devastating artillery (a constant American advantage in this war). Arista eventually ordered his troops to retreat. The next day, Taylor caught up with him and attacked at Resaca de la Palma. Taylor’s men found a vulnerable flank in the Mexican line, overwhelmed it, and sent the entire Mexican army into a panicked retreat. Resaca de la Palma was an overwhelming American victory. Arista’s unnerved survivors retreated, in a total rout, to the Rio Grande. In the two days of fighting, the Americans lost 200 killed and wounded, the Mexicans 600.

The siege of Fort Brown

Even as Taylor fought at Palo Alto and Resaca de la Palma, the Mexicans surrounded Fort Brown. The fort’s garrison was under the command of Maj. Jacob Brown, a well-liked, 58-year-old Vermonter who had started his career as an enlisted soldier and earned an officer’s commission for his combat bravery in the War of 1812.

Day and night, the Mexicans pounded Brown’s men with artillery fire. In the space of one 24-hour period, they fired nearly 1,300 cannonballs at the fort. The Americans dug deep bunkers and hurled artillery back at the Mexicans. In spite of the constant Mexican fire, the U.S. garrison suffered few casualties. The Mexican balls couldn’t penetrate the well-constructed American fortifications. The main danger for the U.S. soldiers was a direct hit. One man took a cannonball in the chin that blew his head off. A few days later, an iron ball shattered one of Maj. Brown’s legs, forcing an amputation. He later died. The siege lasted a week. For that entire time, the Americans girded themselves for a Mexican attack that never came. The victories at Palo Alto and Resaca de la Palma allowed Taylor to break the siege and save the fort. In all, 2 Americans were killed and 13 wounded during the siege.

The original name for Fort Brown was Fort Texas. However, the men who manned the fort so revered Maj. Brown that, when he died, they renamed the fort for him. Later, the town of Brownsville, Texas, would also be named after him.

Invading northern Mexico

After relieving Fort Brown and winning two major battles, Taylor had the initiative. Arista’s army was in total disarray. He asked Taylor for a truce, but Taylor would have none of it. Seizing on his advantage, Taylor crossed the Rio Grande on May 19. Over the course of the summer, his army took the towns of Matamoros and Camargo. Their ultimate objective was Monterrey, a beautiful city at the foot of the Sierra Madre Mountains.

The Battle of Monterrey

The Mexicans fortified the town and many of its key approaches, but not the formidable foothills that brooded over the southern edge of Monterrey. This was a mistake. Thanks to the efforts of his engineers (a real American strength in this war), Taylor discovered he could swing his army around the Mexican defenses to the high ground.

Starting on September 20, 1846, Taylor did just that. Part of his army attacked Monterrey, tying up most of the Mexican defenders. In the meantime, the rest of the army swung around the town, skirmishing with Mexican roadblocks, before capturing the key hills. With this accomplished, the Americans could now attack Monterrey from both sides. What followed was a bitter urban battle, with Americans fighting house-to-house. Small groups would blow holes in a house, assault it, and repeat the process. It was exhausting but effective. Monterrey fell on September 23. The Americans suffered 561 casualties at Monterrey, the Mexicans 367.

With the fall of Monterrey, Gen. Taylor agreed to a two-month armistice (a temporary stop to the fighting that all sides agree to) with the Mexicans. This cease-fire allowed the Mexican army to retreat, intact, farther to the south. Taylor agreed to this armistice because his army was overstretched, tired, and deep in enemy country. President Polk, when he found out what Taylor had done, was enraged. He believed that only the president had the power to conclude an armistice, not a general in the field. He also thought that letting the Mexican army escape was a real blunder on Taylor’s part.

The Battle of Buena Vista

Amid the political turmoil in Mexico, Gen. Santa Anna maneuvered his way into power (he had ruled Mexico ten years earlier as well). Taking control of the army and the government, he amassed a force of 15,000 soldiers to crush Taylor’s army. In early 1847, Taylor entrenched his 4,600 troops at a mountain pass called Buena Vista.

With such an advantage in numbers, Santa Anna called on Taylor to surrender, but the old general refused. On February 22, 1847, Santa Anna launched an attack.

Mexican cavalry and infantry gnawed at the flanks of Taylor’s position while another force, consisting mainly of infantry, came forward in a head-on assault. The American soldiers fought ferociously, and so did the Mexicans. Just when it seemed as if the Mexicans might break the U.S. lines and crush Taylor’s army, his artillery began to decimate the enemy formations. Devastating, accurate artillery fire sliced through the Mexican ranks, demoralizing them and sending them into a broken retreat. Buena Vista ended in a humiliating defeat for Santa Anna. He retreated back to Mexico City, leaving Taylor in possession of northern Mexico.

The fighting Irish Catholics of St. Patrick’s Battalion

At the time of the Mexican-American War, Mexico was predominantly Catholic. The United States was mostly Protestant. Some Protestant Americans didn’t exactly welcome Catholic immigrants from places such as Ireland and Germany. Some of those Catholic immigrants, with limited employment opportunities, joined the Army.

When war with Mexico came, about 800 of these men, most of whom were Irish, decided they couldn’t fight fellow Catholics. They defected to the Mexican side, forming themselves into the so-called St. Patrick’s Battalion.

Men from this battalion fought in many of the major battles of the war. When the Americans captured them, they hanged them for treason. Several dozen met this unhappy fate. Those who survived the war generally went back to Europe or settled in Mexico.

In a classic example of differences in historical interpretation, Americans still view these men as traitors, while Mexicans see them as heroic martyrs. Even today, the St. Patrick’s Battalion is commemorated in Mexico each year on — you guessed it — St. Patrick’s Day.

Seizing the Southwest

The New Mexico and California territories, comprising much of the present-day American Southwest, were lightly populated, barely defended, and in general, quite difficult for Mexico to control. With the onset of hostilities, President Polk ordered the Army and Navy to conquer New Mexico and California. Even more than Texas, these were the lands Polk wanted for the United States. California, with its long Pacific coastline, favorable climate, and sparse population, was especially valuable.

Invading New Mexico

On June 5, 1846, Col. Stephen Watts Kearny and an army of 1,600 soldiers, most of whom were state volunteers, left Fort Leavenworth, Kansas, for Santa Fe, the main Mexican commercial center in the southwest. In two months, they marched 850 miles and took the town against no opposition. Soon after, Kearny was reinforced by another 1,000 volunteers. He detached 1,200 men and placed them under the command of Col. Alexander Doniphan, with orders to take El Paso.

Doniphan, a volunteer from Missouri, marched to El Paso, defeated a Mexican force, and even occupied the northern Mexican state of Chihuahua. With Doniphan’s victory and the bloodless occupation of Santa Fe, the New Mexico territory had fallen to the Americans. Kearny took 300 of his regulars and set out for California, arriving in December 1846.

Bearing down on California

Several months before Kearny left for California, American settlers and a tiny U.S. military force began fighting Mexico. On June 15, 1846, 30 settlers staged a revolt at Sonoma, overwhelmed a small Mexican garrison, and raised a new flag over the town. The flag prominently portrayed a bear, earning the new California the name of the “Bear Flag Republic.” Capt. John Fremont and 62 soldiers arrived in Sonoma a week later to guard the new seat of this newborn republic.

At the same time, naval forces under Commodores John Sloat and Robert Stockton reinforced the Americans. Sloat’s forces took Monterey on July 7. Stockton captured Los Angeles on August 12. Col. Kearny arrived, after an exhausting desert march, in December. Mexican military opposition to all these moves was practically nonexistent. At this point, the Americans seemed to have won another bloodless victory.

However, Spanish-speaking Mexican settlers, generally known as Californios, were determined to remain part of Mexico. Even though they could expect no help from their government in Mexico City, they resisted the American occupation. Throughout the fall of 1846, they fought a series of small battles against the Americans. Dozens died on both sides. In the end, the American military presence was too much for the Californios, who did not have the weapons, resources, or numbers to defeat the U.S.

On January 12, 1847, the last of the Californios surrendered. The next day they signed a peace treaty in Los Angeles with the Americans, yielding control of California to the United States. Most of the Californios then peacefully returned to their California homes.

The agreement that ended the fighting in California was called the Treaty of Cahuenga. Capt. Fremont and Gen. Andres Pico, the Mexican governor of California, signed the treaty on a kitchen table in a comfortable adobe house belonging to Tomas Feliz, in what would someday be North Hollywood.

Gen. Winfield Scott’s Incredible Campaign

By early 1847, the United States was clearly winning the war. After all, the Americans had conquered New Mexico and California. They had pushed the Mexicans out of Texas, seized control of Monterrey and northern Mexico, and the Navy was enforcing a partial blockade of the Mexican east coast. President Polk wanted to end the war now. In his view, the Mexicans should bow to reason, agree to end the war, and accept American money for the territory American soldiers had taken in battle. But Santa Anna would have none of this. He still hoped to turn the tables on the Americans and win the war.

Frustrated and angry by Santa Anna’s refusal to call it quits, Polk ordered an amphibious force under Gen. Winfield Scott to invade central Mexico and capture the enemy capital. The president hoped that perhaps this invasion would change Santa Anna’s attitude and end the war.

Polk chose Scott to lead this expedition for two reasons. First, the president had lost confidence in Gen. Taylor because of the armistice he had negotiated with the Mexicans after the Battle of Monterrey. Second, he knew that Taylor was a Whig and that his battlefield victories had made him a national hero. Sensing this, Polk wanted to eliminate him as a potential political rival. So the president stripped Taylor’s army of its best troops and gave them to Scott for his invasion. Ironically enough, this move infuriated Taylor so much that it helped persuade him to get into politics!

Winfield Scott — the embodiment of the Army

By 1847, Winfield Scott was 60 years old and had been in the Army for 40 years. Although he had never attended West Point, he was the consummate military professional. He had fought in the War of 1812, earning a reputation as an excellent combat leader at such battles as Lundy’s Lane and Chippewa (see Chapter 9).

In the years that followed, while serving in a variety of posts, Scott emerged as the Army’s leading intellectual, not to mention one of its finest officers. He wrote the service’s manuals on infantry tactics, training, and preparation for combat. He brought professionalism and constancy to an army that badly needed it.

Scott had two nicknames. Those who liked him called him the “Grand Old Man of the Army.” Those who didn’t like him referred to him as “Old Fuss and Feathers” for his stern, overbearing nature. Like him or not, no one was better qualified than Gen. Scott to command the invasion of Mexico.

Invading at Veracruz

Gen. Scott chose to invade at Veracruz, a port city on Mexico’s east coast, some 250 miles east of Mexico City. Gen. Scott’s invasion force was 12,000 men strong and consisted of volunteers and regulars. Scott worked well with Commodore Matthew Perry, the naval officer whose ships transported the soldiers. The two men coordinated an invasion plan, skirting past Veracruz’s considerable coastal guns and landing on March 9, 1847, against little opposition at beaches south of town. Scott had specially requested special surfboats to transport his soldiers from the main ships to the beach. The boats worked well. Each of them could carry between 50 and 80 soldiers. With his army safely ashore, Gen. Scott successfully besieged Veracruz, forcing its surrender on March 28.

Scott’s casualties during the siege were light — 80 men killed and wounded. But he was worried. Yellow fever was eating away at his army. Hundreds were sick and the problem would only get worse with warmer spring weather. Using Veracruz as his main supply port, he marched 8,500 soldiers west, to higher, healthier ground, along a new national highway the Mexicans had built. The ultimate objective was, of course, still Mexico City, which Americans called “The Halls of Montezuma” after the famous Aztec ruler. Scott and his army headed straight for this hallowed city.

If you were a soldier in the Mexican-American War, disease was a greater threat to your life than bullets. Of the 13,000 American soldiers who lost their lives in the war, only 1,700 were killed in combat. The rest died of disease or accidents. The ratios were largely the same for the Mexicans.

Battling at Cerro Gordo

Santa Anna reacted to Scott’s invasion by raising a new army through conscription (a draft) and appeals to patriotism. The Mexican leader intended to stop Scott about 150 miles east of Mexico City in the mountains. He entrenched a considerable force of 12,000 soldiers in the foothills and mountains around a tiny village called Cerro Gordo. Santa Anna knew that to move west on the road to Mexico City, Scott’s army had to get through his entrenched army. In Santa Anna’s view, this would force the Americans to assault his dug-in troops, leading to a slaughter.

Scott did not oblige him. Thanks to the efforts of a brilliant engineer captain and future Civil War general named Robert E. Lee (see Chapter 11), Scott devised an ingenious plan to flank Santa Anna’s defenses. Lee and his colleague, Lt. Pierre Beauregard — another future Civil War general — had found an unguarded trail that offered a way around the main Mexican defenses. Gen. Scott decided to move the bulk of his army along that trail and attack the flank of the Mexican line. In the meantime, a smaller American force would advance toward Santa Anna’s main defenses, right where he expected them to attack. This would divert Mexican attention from the main American attack on their flank.

On April 18, 1847, Scott sent his men forward. The plan worked better than the general could have ever imagined. In a matter of hours, the Americans unhinged the entire Mexican line, killing, wounding, or capturing nearly one-third of the enemy defenders. Santa Anna and the remnants of his army retreated in disarray all the way to Mexico City. The Americans lost 417 men at Cerro Gordo; the Mexicans lost 4,000.

In the wake of his victory at Cerro Gordo, Scott pushed west to Puebla. Sickness, lack of supplies, and the enlistment expiration of many of his state volunteers forced him to halt at Puebla. The Americans spent much of the summer regaining their strength for the final push to Mexico City. Knowing he was deep in foreign territory and heavily outnumbered, Gen. Scott wisely cultivated good relations with the Mexican people. He made sure his soldiers paid for food, clothing, and other items. He developed friendly relationships with many local leaders. By late summer, many Mexicans were either on his side, neutral, or simply against Santa Anna.

Future generals in the Mexican-American War

Nearly all the generals who earned fame in the Civil War — whether northern or southern — served in the Mexican-American War.

Robert E. Lee and Pierre Beauregard served as engineer officers on Winfield Scott’s staff.

Ulysses S. Grant fought in nearly every battle, including the urban combat at Monterrey.

George B. McClellan was in the climactic battles in and around Mexico City.

Thomas “Stonewall” Jackson was an artillery officer whose guns pounded Mexican lines during the siege at Veracruz and the assault on Mexico City.

Braxton Bragg was also an artilleryman, most notably at Fort Brown.

Ambrose Burnside served under Bragg for part of the war.

George Pickett led assault troops at Mexico City.

Joe Hooker and George Meade were on the staffs of both Zachary Taylor and Scott.

All these men were West Point–trained military professionals. During the war with Mexico, they were united as Americans, but a decade and a half later, they were mortal enemies when the Civil War broke out. As generals, all of them drew heavily on their Mexican-American War experiences.

On to Mexico City

In the late summer of 1847, Scott’s army marched west with the goal of taking Mexico City. Santa Anna still refused to make peace, so Scott unleashed a new series of flanking maneuvers, swinging his army south of Mexico City. The Americans fought and won battles at Contreras, Churubusco, Molino del Rey, and Chapultepec. Scott’s soldiers entered Mexico City itself on September 14, 1847. Santa Anna fell from power and fled.

The End of the War

In his campaign to take Mexico City, Scott lost 3,000 men killed in battle, wounded, and felled by disease. The remnants of his army occupied the city as best they could. Once again, Scott made a point of cultivating good relations with the locals. Mexico was in political chaos. The Americans wanted to end the war, but it was hard to find proper authorities who were willing to negotiate. Throughout the fall of 1847, Scott’s victorious army continued to occupy the Mexican capital. Finally, in early 1848, Mexico and the U.S. negotiated a peace treaty.

The Treaty of Guadalupe Hidalgo

The Mexican-American War officially ended on February 2, 1848, with the signing of the Treaty of Guadalupe Hidalgo. The treaty gave the U.S. control of Texas, fixed the Mexican-American boundary at the Rio Grande, and ceded the territories of California and New Mexico to the Americans. In return, the Mexicans received $15 million, less than half of what Polk had originally offered before the war.

The war’s legacies

The Mexican-American War was deeply consequential, with lasting legacies:

Stretching all the way to the Pacific Ocean, the U.S. became a truly continental power, winning half a million square miles of land. The states of California, Texas, New Mexico, and Arizona all came at the expense of Mexico, as did parts of Colorado, Nevada, and Utah.

The acquisition of so much territory led to a furious debate in the United States over the potential expansion of slavery, and this was a major cause of the Civil War.

The war solidified the notion of Manifest Destiny in America.