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A Clear Conscience

LITTLE DID ABRAHAM LINCOLN know it, but he was not far from the mark when he described the president as finding himself “he knows not where” in the middle of January. Polk probably wouldn’t have admitted it to anyone but Sarah, but matters had spiraled out of his control. Trist was negotiating without authority, and with each day that passed, Polk felt more strongly than ever that Trist’s terms were too generous to Mexico. Under the influence of the aggressive expansionists in his cabinet, the president had concluded that the ideal location for a boundary would fall somewhere along the twenty-sixth parallel, running directly west from Matamoros below the southern tip of Texas at the Rio Grande, including at least a portion of Baja California. This would have given the United States another 187,000 square miles, or about a third more of Mexico than in the terms of the treaty he had delivered to Nicholas Trist. On January 2, Polk informed his cabinet that at the very least, “we might accede to a cession of New Mexico, the two Californias, and the passage across the Isthmus of Tehuantepec, paying for them a much less sum than Mr. Trist had been authorized to offer, and that we should in addition secure the port of Tampico.”¹

But Polk had no idea what was happening in Mexico. “Neither General Scott nor Trist has written a line to the Government by the train that left Mexico on the 13th of January,” he fumed in his diary in early February. “There is a conspiracy” between Scott and Trist, he was sure, “to put the government at defiance and make a treaty of some sort.” Had Polk known the true condition of matters in the Mexican capital, he would not have been reassured. In the final weeks of January, wealthy Mexican supporters of American annexation offered General Scott $1.25 million to accept the presidency of Mexico and oversee the annexation of the country to the United States. Mexican annexationists invited other American officers, including Ulysses S. Grant, to meetings to discuss the issue. At the end of January, Manuel Zamorg, a major in the Mexican national guard, warned a member of the Mexican legation in Paris about the “lamentable” condition “into which our beloved country is drifting. Mexico is beginning to be erased for the catalogue of nations,” he wrote. “The Yankees are already in possession of two thirds of the country.… [A]ll the elements of a prompt and complete dissolution exist.” Britain’s minister to the United States wrote back to London that “there is a growing conviction in the minds of the people” that all of Mexico would be annexed.²

ANNEXING MEXICO This map illustrates potential annexations contemplated by the Polk administration in the fall of 1847 as well as the limited territorial cession initially offered by Mexican negotiators. Some Democratic expansionists hoped to take all of Mexico as spoils of war. Many Whigs, including Henry Clay, argued against taking any territory. (photo credit 13.m1)

Scott had no interest in becoming president of Mexico, nor did he want to see Mexico annexed to the United States. Grant wanted nothing more than to go home. However they might feel about the people of Mexico or prospects for annexation, the soldiers, to a man, wanted the war over. “I hope there may be peace,” one soldier wrote home to his family in New Orleans in February, “for I have not a hostile feeling against these Mexicanos tho’ I … believe they prove treacherous more than any people I know.” War had lost its appeal. Looking around at “some of the sad effects of war in the wasted forms of soldiers & others with loss of arms &c,” this soldier wondered, “how much misery and distress is caused in the beautiful world of ours by sin.”³

Scott understood the political divisions that were making it difficult for Mexicans to agree on a treaty, but the fact was that any day an officer might arrive from the United States with orders to physically remove Nicholas Trist from army headquarters. Clearly there was no more time for negotiation. Unless a treaty was signed immediately, Scott threatened, he would march his troops into the countryside and resume warfare against the Mexican people.

Provisional president Manuel de la Peña y Peña, recognizing the imminent danger to the continued existence of Mexico, gave his permission to the Mexican commissioners to sign a treaty of peace with Trist. His decision, the commissioners were told, was based on a number of factors, including “the extreme scantiness of resources,… the probability that the United States may prove every day more exacting in their demands,” and the “duty” of the government “to put an end to the calamities from which the country is suffering and of checking the projects of annexation to North America.”⁴

Trist and his Mexican counterparts met in the town of Guadalupe Hidalgo. The location was no accident. Guadalupe Hidalgo was considered by the people of Mexico “the most sacred” spot “on earth, as being the scene of the miraculous appearance of the Virgin for the purpose of declaring that Mexico was taken under Her protection.”⁵ Mexico, all the commissioners realized, had never been more in need of protection than at that moment.

On February 2, 1848, three Mexican commissioners and one recalled American signed their names to a treaty of peace in the “sanctuary” of the cathedral in Guadalupe Hidalgo. It was a solemn moment. Just before he picked up his pen, one of the men turned to Trist and said, “This must be a proud moment for you; no less proud for you than it is humiliating for us.” Trist replied, “We are making peace, let that be our only thought.” But he admitted to his family, “Could those Mexicans have seen into my heart at that moment, they would have known that my feeling of shame as an American was far stronger than theirs could be as Mexicans.” Trist had felt shame throughout the negotiations, but particularly “at moments when I felt it necessary to insist upon things that they were averse to. Had my course at such moments been governed by my conscience as a man, and my sense of justice as an individual American, I should have yielded in every instance.” But Trist knew full well that his vindictive president would find any opportunity to reject a treaty he had negotiated against orders, both out of anger at his betrayal and from the belief that a future treaty would bring more of Mexico into American hands.⁶

Trist did not yield. The terms of the Treaty of Guadalupe Hidalgo aligned closely with those Polk had specified in his original document, with the exception of the fact that Mexico kept Baja California. Trist was even savvy enough to authorize a U.S. payment of only fifteen million dollars in exchange for 525,000 square miles of Mexican land, when Polk had specified a maximum of twenty million. The United States agreed to recognize Mexican land grants and property rights, to provide a route to citizenship for those Mexican residents of the annexed territories who remained in what was now the United States, and to restrain raiding by Indian tribes over the border into Mexico, although none of these three promises would be fully met by the United States. Mexico relinquished all claims to Texas and recognized the Rio Grande as the border between Mexico and the United States.

It was not the most generous treaty Trist could have negotiated, but it was perhaps the most generous the president would accept. He hoped Polk would accept it. But Trist had no sense of what would happen, either to the treaty or to him. That his career in Washington was over was clear. The day before he put his signature on the document, he wrote his wife, Virginia, “I will live on bread and water before I will again hold office of any kind.”⁷ He had no idea how close to the mark this prediction would be. But he knew with absolute certainty that he had done the right thing, both for Mexico and for the United States. His “conscience as a man” was clear.

James Freaner, the New Orleans correspondent who had advised Trist to continue negotiating the treaty after his recall, rushed the treaty to Washington in just seventeen days, a record for any war correspondence. He arrived at James Buchanan’s Washington home after dark, looking every bit like a person who hadn’t bathed or slept in days. Buchanan immediately brought the treaty to the White House, and at 9:00 p.m. on February 19 began reading it out loud to an incredulous president. They discussed it together, and then Buchanan returned home.

Polk was left alone with the treaty of peace that he had so long wished for but was unsure he could accept. He stayed up late into the night reading it over. He was keenly aware of the country’s war fatigue. Nothing he did or said seemed to diminish it. Though Democrats would not stop calling for the annexation of all of Mexico, he knew full well that the antiwar movement was in the ascendancy. “Mr. Trist had acted very badly,” he wrote in his diary before going to bed, “but notwithstanding this, if on further examination the Treaty is one that can be accepted, it should not be rejected on account of his bad conduct.”⁸

After lengthy and animated cabinet discussions the next day, Polk concluded that he had to accept Trist’s treaty. He didn’t want to accept it, and Buchanan and Walker insisted he reject it and demand more land from Mexico. “If the treaty was now to be made,” he fumed, “I should demand more territory, perhaps to make the Sierra Madre the line.” Sonora, Chihuahua, and Coahuila were relatively unpopulated, and legendary for their mineral wealth. The acquisition of that territory would also ensure good land for a southern transcontinental railroad route, an objective fervently desired by the businessmen of the South. The coastal territory of Baja California offered access to both the Pacific Ocean and the Gulf of California. It didn’t take a visionary to see that this land could be valuable to the United States, and that the United States would make good use of it.⁹

But given the hostility of Congress, Polk felt he had little choice but to submit the treaty to the Senate for ratification. Because were he to reject Trist’s treaty, what would be the “consequences”? “A majority of one branch of Congress is opposed to my administration; they have falsely charged that the war was brought on and is continued by me with a view to the conquest of Mexico,” Polk wrote. “If I were now to reject a treaty made upon my own terms … the probability is that Congress would not grant either men or money to prosecute the war … and I might … lose the two Provinces of New Mexico and Upper California, which were ceded to the United States by this treaty.”¹⁰

Trist’s treaty was far from perfect, but it was the best option open to him. At least it guaranteed the acquisition of California. Polk had entered office intent on bringing California into the Union. Trist’s treaty ensured that America’s destiny on the Pacific would be fulfilled. Polk’s destiny, as the agent of American empire, was also fulfilled. At noon on February 21, the president called his cabinet together and announced his decision to submit the Treaty of Guadalupe Hidalgo to the Senate for ratification. When James Buchanan tried to talk him out of it, insisting on the need for a greater territorial cession, Polk chastised him, reminding the presidential hopeful that at the start of the war Buchanan had been opposed to taking any territory from Mexico at all. Polk’s mind was made up; the last thing he needed now was politically motivated antagonism in his own cabinet. “No candidate for the Presidency ought ever to remain in the Cabinet,” he sighed to his diary later that night.¹¹

News of the treaty swept through Washington. Before seeing so much as a draft, congressmen were passing judgment on it. Many agreed with Buchanan that the terms were far too lenient to Mexico. A large number of Whigs adopted the opposite view, that any territorial cession was too much. And members of both parties asked whether it was right to consider a treaty negotiated by a recalled commissioner.

But the same day Polk submitted the Treaty of Guadalupe Hidalgo to the Senate, John Quincy Adams collapsed in his seat in the House of Representatives in a paralytic stroke. He was just about to cast his final antiwar vote, against a resolution of thanks to army officers in Mexico. Discussion of the treaty abruptly ceased; balls and dinners in honor of George Washington’s birthday were canceled. Adams regained consciousness long enough to ask for Henry Clay. Weeping, Clay was brought to his side and clasped his hand. Two days later, on February 23, 1848, the great antislavery voice died.

Polk raised black crepe over the front door of the White House and ordered all government business suspended for two days. And as he sat down to write in his diary at the end of another long day, he thought about his place in history. “The first seven Presidents are all now dead,” he wrote in his characteristically unsentimental manner. “The ninth President is also dead. Mr. Van Buren who was the eighth President and Mr. Tyler … are the only two of my predecessors who now survive.” But this brush with mortality did nothing to ease his hatred of Nicholas Trist. After reading some of the “arrogant, highly exceptional, & … insulting” dispatches sent by Trist with the treaty, Polk finally sent an order for the diplomat to be bodily removed from the headquarters of the army in Mexico and escorted to Veracruz.¹²

Abraham Lincoln was also thinking about mortality. After witnessing Adams’s collapse in the House, he learned he was to be a pallbearer in the elaborate state funeral. He, along with other congressional Whigs, escorted Adams’s remains to “the place designated for interment.” Only a few days later, while gloomy letters from Illinois about his “Spotty” reputation back home were arriving by mail, Lincoln cast his first antislavery vote as a congressman. He voted in support of the Wilmot Proviso banning slavery from all territory gained from Mexico, which was once again being introduced by northerners despite the fact that it had no chance of passing in the southern-controlled Senate. The proviso had twice been approved in the House since it was initially introduced by David Wilmot, and twice it had been defeated in the Senate.¹³

Lincoln had always been quiet about slavery. During his congressional campaign, he had avoided any mention of the topic. No more. After several meetings with his housemate Joshua Giddings, Lincoln began preparing resolutions to abolish slavery in Washington, D.C. The freshman congressman from Illinois and the abolitionist worked together on a gradual emancipation bill, which offered compensation to slave owners for their property. Joshua Giddings praised the bill. In 1860 he reminded abolitionists that Lincoln had “cast aside the shackles of his party and took his stand … laboring in the cause of humanity” with the bill. But in the end Lincoln did not introduce it to Congress. He delivered speeches alongside abolitionist congressional Whigs. The old economic questions that used to inspire him up until now took a backseat to issues of liberty and freedom.¹⁴

And he could take pride in the role he played in ending the war. Whatever reservations senators on both sides of the aisle held about the Treaty of Guadalupe Hidalgo were muted in the solemn days following John Quincy Adams’s funeral. After revising articles in the treaty that would recognize Spanish and Mexican land grants, and modifying the language about citizenship, the treaty overwhelmingly passed the Senate on March 10. And on May 19, almost exactly two years after the U.S. Congress had first assented to Polk’s war bill, Mexico’s Congress ratified the revised treaty. San Francisco was alive with rumors of gold in the California hills that spring, but as so often was the case in the course of the war, limited communication made all the difference. Mexico City didn’t receive news about the astounding find at Sutter’s Mill until three months after signing ownership of its El Dorado over to the United States.

Polk got California, but it was the antiwar movement that conquered a peace. The American public had turned against the war for a number of reasons, not all of which were admirable. Many were motivated by racism, unwilling to offer citizenship to the people of Mexico. The year 1848 marked the first time that the fear of incorporating supposedly “inferior races” into the United States limited the nation’s territorial expansion. Racism would continue to shape anti-imperialism for the rest of the century, most notably when the Senate rejected President Ulysses S. Grant’s treaty to annex the Dominican Republic in 1870 on racial grounds.¹⁵ Others opposed annexing Mexican territory because they feared the increasing power of slaveholders. Some simply concluded that Mexican land wasn’t worth the sacrifice of American blood and money.

But had Nicholas Trist not concluded that justice required him to disobey his president and negotiate a lenient peace treaty with Mexico, no Treaty of Guadalupe Hidalgo would have emerged in 1848. Had Clay not spoken out in Lexington, popular meetings supporting his resolutions would not have bloomed, and congressmen would have restrained their rhetoric. Lincoln might not have opposed the war at all. Had journalists and soldiers lacked the courage to report atrocities, clerics such as Albert Hale might never have preached against the iniquity of the war, and the public would not have understood the true cost of the conflict. Had the people of Massachusetts not protested the war as immoral, the residents of other states would not have known that sustained opposition was both possible and patriotic.

Although Polk never mentioned Lincoln or his attacks directly, the cumulative effect of national antiwar agitation generally, and congressional antiwar agitation in particular, was to limit both the duration of the war and Polk’s demands for Mexican territory. Lincoln’s Spot Resolutions were his signature position in the Thirtieth Congress. Had he chosen to focus on tariffs during the first months of his congressional term, would Polk have felt the same degree of assault from Congress? It is impossible to know for sure, but at the very least Lincoln could conclude that his stance against the war had contributed to Polk’s decision to accept the Treaty of Guadalupe Hidalgo. Charles Averill’s fictional Mexican ranchero attempted to kidnap Nicholas Trist in order to prevent an ignominious peace for Mexico, but the man Illinois Democrats labeled the “Ranchero Spotty” may well have helped Trist accomplish his mission.

Nicholas Trist returned from Mexico to face the enduring contempt of James Polk. The president might sign the treaty, but he would give Trist no credit for it. He fired the “impudent and unqualified scoundrel” and withheld the pay he had earned during his stay in Mexico.¹⁶ Polk did everything in his power to prevent Trist from receiving either credit for his success or future employment. And he carried his hatred of Trist to his grave.

No one came to Trist’s aid, and he proved unsuited “both by taste and qualification” to “the rough roll and tumble contests of professional calling.” In desperate need of funds, he spent the next twenty years battling poverty, renting out rooms in his house, and toiling as paymaster for a railroad company. But he never apologized for his actions in Mexico. In 1848 Trist proudly told the House of Representatives, “If I am to have a fault, I would rather speak too harshly, and thrust forth truth unwisely, than to have played the hypocrite and held truth in.”¹⁷

In 1861 Winfield Scott appealed to the Lincoln administration to appoint Trist revenue collector of Philadelphia, but his petition was ignored. Perhaps Trist was too much of a Democrat for employment in a Republican administration. Or perhaps Lincoln viewed Trist as simply another job seeker, with Scott’s recommendation lacking the weight of one by a Jefferson or Jackson. After all, the two men never knew each other, despite their shared labor in the creation of America’s first national antiwar movement.

It wasn’t until Trist’s seventieth birthday, in 1870, that Congress finally granted the diplomat the back pay he was owed for his service in Mexico, with interest. It was no member of Trist’s beloved Democratic Party who took up his cause, but the Massachusetts antiwar agitator Charles Sumner, the man willing to jettison a lifelong friendship with Robert Winthrop over his war vote. With the sectional issues raised by the U.S.-Mexican War “resolved” through the Civil War, both northerners and southerners found it at last possible to acknowledge the service of Nicholas Trist. President Ulysses S. Grant appointed Trist postmaster of Alexandria, Virginia. Finally, Trist got the posting he had dreamed of, and he spent four happy years there before his death in 1874.

Henry Clay helped to crystallize antiwar sentiment throughout the northern half of the country and to provide a practical outlet for opposition to the war with his call to action. The Lexington resolutions became the Whig platform on the war and were proudly reprinted in the 1848 Whig Almanac. Clay had taken a clear gamble with his courageous speech, but at a cost to his career. It was his willingness to jeopardize his political base in the South that made his words so compelling in the North, and enabled Whigs, Free-Soil Party members, and disaffected northern Democrats to rally around the Lexington resolutions. “It may be that Mr. Clay has uttered the truth too boldly for popularity at the moment,” a correspondent to the Milwaukee Sentinel and Gazette suggested. “But succeeding years will increase the conviction that a truer or bolder man never stood forward to enlighten and guide his countrymen, even against their will.”¹⁸ Although this speech more than any other mobilized the national antiwar movement, it also, in a sense, made Henry Clay the second martyr to the war in his own family.

Nicholas P. Trist, 1855–65. Polk never forgave Trist for disobeying his orders. Exiled from the State Department, Trist spent the following two decades in poverty. Library of Congress Prints and Photographs Division. (photo credit 13.1)

For Henry Clay would not win the presidential nomination in 1848.

It was his Lexington speech that killed his candidacy. One longtime “sincere friend” of Abraham Lincoln’s, the Tazewell (Illinois) Whig editor Anson G. Henry, wrote Lincoln not long after he heard about the speech. Henry believed that the territorial position Clay had staked out would be fatal to the Whig Party. He admitted to Lincoln that he felt “a very great anxiety to know what course you design taking in relation to the Mexican War. I hope you will not feel disposed to go with Mr. Clay against all Territory.” He predicted that “that speech of Mr Clay will beat us as a party for years to come, unless we can unite upon ‘Old Zach.’ ”¹⁹

In fact, Anson Henry’s concern about the electability of antiwar Whigs was shared by Lincoln. As much as Lincoln admired Henry Clay, he agreed that the Sage of Ashland’s courageous Lexington speech doomed him as a candidate. He voted against a “no territory” resolution in early January when one appeared before Congress.²⁰

And so, even while attacking Polk on the floor of Congress, Abraham Lincoln began to work for Zachary Taylor’s election. As the lone Whig from Illinois in Congress, he was in a unique position to shape Taylor’s candidacy. In notes he prepared in January 1848 for a speech to be delivered by the presidential candidate and war hero, Lincoln suggested that Taylor tell his audience: “As to the Mexican war, I still think the defensive line policy the best to terminate it—In a final treaty of peace, we shall probably be under a sort of necessity of taking some teritory; but it is my desire that we shall not acquire any extending so far South as to enlarge and agrivate the distracting question of slavery—Should I come into the presidency before these questions shall be settled, I should act in relation to them in accordance with the views here expressed.”²¹ One of Clay’s most adoring supporters, a man who devoted his congressional term to reiterating many of the things he had heard in Lexington on a rainy afternoon, turned against Clay in 1848.

The Whigs had their second and final victory in a presidential election that year, as in 1840, with a war hero at the head of the ticket. Southerners mistakenly supposed that General Taylor, a Louisiana slaveholder, would protect their interests. But when it came time for California to enter the Union, Taylor supported the Wilmot Proviso, leading infuriated southerners to threaten secession unless Mexican Cession lands were opened up to slavery.

Henry Clay, unelectable nationally, returned to the Senate in 1849. The following year, Clay introduced the Compromise of 1850. His omnibus bill failed to receive a majority, but once again his powers of persuasion proved crucial in saving the nation. Illinois Democrat Stephen A. Douglas engineered the separate passage of all the bills contained in Clay’s original proposal. It brought California into the Union as a free state, finally resolved Texas’s lingering boundary claims over New Mexico, and temporarily averted disunion. Mississippi senator Henry Foote, who drew a pistol on Thomas Hart Benton during the heated debate in 1850, later wrote, “Had there been one such man in the Congress of the United States as Henry Clay in 1860–61, there would, I feel sure, have been no Civil War.”²² Clay died less than two years after the passage of the 1850 compromise.

Henry Clay, ca. 1850. Portrait by Mathew Brady. Clay as he appeared the year of his final great compromise. Library of Congress Prints and Photographs Division. (photo credit 13.2)

Polk left the presidential office in the hands of the Whig general he had inadvertently made famous. As he slowly returned to Nashville with Sarah, he thought about similar trips he had made in the past. He reminisced about the trip with Jackson at the close of his remarkable presidency, when Old Hickory told Sarah she would one day be First Lady. And of course he remembered the trip north to Washington at the start of his own term. Now things had come full circle. He was the president returning home after his own remarkably successful term in office. He had lived up to Jackson’s example and fulfilled Old Hickory’s mission. The couple was feted in every town along the route, just as Jackson had been. But James found he had just a fraction of his old energy. They all wanted him to speak, and he “felt it was right to do so.” But Sarah cut his addresses short; she couldn’t shake the “feeling” that James’s “life was at stake.”²³

The trip nearly killed him. Sarah never forgot how much “this triumphal progress” weakened her husband. By the time they reached their new home in Nashville, Polk Place, his condition was obvious to everyone. The Nashville Union wrote that at his reception, “the feebleness of the late President was apparent,” and “the most intense anxiety for his health has pervaded the city.”²⁴

Three months later, Polk was dead. Few doubted that he had worked himself to death. And yet during his single brilliant term, he accomplished a feat that earlier presidents would have considered impossible. With the help of his wife, Sarah, he masterminded, provoked, and successfully prosecuted a war that turned the United States into a world power. To James and Sarah Polk, the war was not an unjust conflict, an unethical clash; it was a patriotic mission. Sarah dismissed the protests just as her husband had done. “Of course there were some opposed,” she told a Nashville reporter, “there is always somebody opposed to everything.” But until the end of her life she maintained that the acquisition of Texas, California, and New Mexico were “among the most important events in the history of this country.”²⁵ With his conscience clear, James K. Polk, on his deathbed, asked to be baptized. Distancing himself from Sarah for one of the few times in his life, he joined not her Presbyterian Church but that of the Methodists.

Though three men of conscience had sacrificed careers to oppose him, had even managed to bring a “wicked war” to a close, it was Polk who was triumphant. Mexico lost half its territory. Gone were the provinces of Alta California, Nuevo Mexico, and parts of Tamaulipas, Coahuila, and Sonora. That land became California, Nevada, and Utah, and parts of Arizona, New Mexico, Oklahoma, Kansas, Colorado, and Texas. In total more than 12,500 U.S. soldiers perished, as well as at least 25,000 Mexicans. It was the crowning moment for Manifest Destiny and fed the dreams of those Americans who believed the United States should take even more territory by force, dreams that had their realization in the Spanish-American War of 1898.²⁶

But Polk’s war didn’t merely change the country’s face. It set a number of precedents that would shape the future of American diplomacy and warfare. His was the first American war against a neighboring republic, the first started with a presidential lie, and the first that a large number of American people felt guilty about.

Beyond these firsts, the U.S.-Mexican War had an explicit catastrophic impact: it fractured the delicate sectional balance within the United States. Ralph Waldo Emerson famously predicted in 1846 that the United States would defeat Mexico but that “Mexico will poison us.” The poison took effect immediately. When once it had been understood where it was legal to own slaves and where it was not, that stability was now disturbed. News of gold at Sutter’s Mill brought a hundred thousand people to California in a little more than a year. In 1848 and again in early 1849, James K. Polk appealed to Congress to grant California territorial status, but the issue of slavery made it impossible for representatives to reach an agreement. Southerners had already brought their slaves to California, but the majority of settlers were adamantly opposed to slavery. Southerners refused to accept that they and their slaves would be banned from the Mexican lands they had shed so much blood for. Northerners were equally adamant that their sacrifice translate into “free soil” where they and their children could work free from association with slavery. Victory in Mexico spurred expansionists in both sections of the country to push for more land, in Hawaii, Central America, the Yucatán, and particularly Cuba, further exacerbating sectional tensions. The stage was set for secession. It was an argument that could not be settled with words.²⁷

The war raised fundamental questions, questions that proved too painful to answer at the time. After dismantling a neighboring republic for the sole purpose of aggrandizement, could the United States any longer make claims to altruism in international affairs? After Polk provoked a war and then lied to Congress about it, could presidents be trusted to behave honestly in matters of life and death? After annexing Mexico’s northwest, could the United States still contrast its acts with the imperialist oppression of its then-nemesis, Britain? Why had it been so easy to manipulate the American public to support a war as contrary to American principles as this one? How could the opposition party so readily surrender its objections as the Whigs did in 1846?

The conflict Polk engineered became the transformative event of the era. It not only changed the nation but also created a new generation of leaders, for good and for ill. In the military, Robert E. Lee, Ulysses S. Grant, Stonewall Jackson, George Meade, and Jefferson Davis all first experienced military command in Mexico. It was there that they learned the basis of the strategy and tactics that dominated the Civil War. Polk’s war also catapulted the officers Zachary Taylor and Franklin Pierce into presidencies for which they were woefully ill equipped.

Then there was the congressman from Illinois.

In 1848 a Democrat won election to Congress from the Seventh Congressional District. The seat held by Hardin, Baker, and Lincoln was no longer safe for the Whigs. Many blamed Lincoln’s antiwar activism for the loss. Lincoln returned home in 1849 and did not run again for Congress. But he had learned something that might now be called Lincolnesque: the necessity of melding political and ethical considerations. As he protested the war and condemned slavery, he was not embracing a simple politics of morality, though it must often have seemed to his few supporters that his sense of decency was mangling his ambition. In fact, he was learning to avoid false dichotomies between morality and hard political decisions. The war showed him how to make ambition, ethics, and politics work in concert. He helped to bring the war to a close, and then helped elect a war hero from his own party to the presidency.²⁸

But he never forgot Henry Clay. When Clay died in Washington in 1852, Lincoln delivered a eulogy at the Springfield statehouse. Most of Clay’s eulogists praised his genius for compromise. Lincoln did not. He focused instead on Clay’s “devotion to human liberty.” Lincoln’s portrait of Clay was of a man who sacrificed for what was right. “The long enduring spell with which the souls of men were bound to him, is a miracle,” Lincoln proclaimed.²⁹ Taking a stand against the U.S.-Mexican War helped make Clay great. Taking a similar stand made Lincoln a better politician, and perhaps also a better person.

Ten years later, when he ran for the Senate, the people of Illinois had not forgotten what he’d said about the war. Despite the fact that Lincoln was careful while in Congress to always vote for supplies for the troops, his words haunted him politically for the rest of his life. During their famed 1858 senatorial campaign debates, Stephen A. Douglas reminded the Illinois public that “whilst in Congress” Lincoln “distinguished himself by his opposition to the Mexican War, taking the side of the common enemy against his own country; and when he returned home he found that the indignation of the people followed him everywhere, and he was again submerged or obliged to retire into private life, forgotten by his former friends.” The editor of the Chicago Tribune wrote a confidential letter to Lincoln afterward, warning the candidate that Douglas’s charges were “calculated to do mischief” among potential Republican voters. “Tens of thousands of our party are old Democrats, and you know their sentiments on this Mexican War supply question.”³⁰

Again in 1860, Lincoln’s opponents revisited the legend of the Ranchero Spotty, accusing him of aiding and abetting the enemy in 1848. The charges did not fall on dull ears, as questions about Lincoln’s patriotism and actions at that time remained unresolved among voters of all educational levels. One “undisided yet … honest man” wrote Republican candidate Lincoln in 1860 to ask two questions. “The first is this did you vote against sending provisions to the soldiers when they was in mexico … the second is this did you refuse to vote A bill of thanks to the soldiers that fought in mexico did you say that you would not vote A bill of thanks to the soldiers without they would add this amendment to it. that it was an injust war.”³¹

A New York iron merchant also hoped for clarification before casting his vote in 1860. On business stationery featuring an attractive representation of his spacious iron dealership, William H. Wilson queried Lincoln, “Will you be kind enough to say if you did or did not while you were in congress vote against supplies to the american army while on the Battle fields of Mexico. The charge has been brought forward by your opponents and I have as often charged it to be a falsehood and although opposed to betting I as a last resort have agreed to back my opinion that such was not the fact.”³²

Lincoln won in 1860, of course. And while America’s unjust war of imperial desire shoved the nation into the most horrible of national fractures, yet at the same it time helped create the leader who was able to reunite the states. It was Lincoln who would prove the greatest man of his generation, not Polk, Clay, Trist, or his once unstoppable rival, John Hardin. The Battle of Buena Vista and its pantheon of heroes had faded from memory by the time Abraham Lincoln lost his life in the service of his country eighteen years later.