A Wicked War

Historian Amy S. Greenberg tells the story of the U.S.-Mexican War (1846–48) through the interconnected lives of five men: Henry Clay, the elder statesman of the Whig Party; James K. Polk, the expansionist Democratic president who engineered the conflict; Abraham Lincoln, a young Illinois politician; John J. Hardin, a congressman and militia general from Illinois; and Nicholas Trist, a State Department official and grandson-in-law of Thomas Jefferson. Greenberg argues that the war was an act of territorial aggression that reshaped the nation into a continental power and tipped the sectional struggle over slavery toward civil war. She contends that a vibrant antiwar movement, largely overlooked by historians, constrained Polk's ambitions and prevented the total annexation of Mexico.

The narrative opens in 1844, when the question of annexing the Republic of Texas upended the presidential race. Henry Clay, the presumptive Whig nominee and one of the most powerful figures in American politics, dismissed warnings that President John Tyler was secretly negotiating an annexation treaty. Clay published a letter opposing annexation, warning it would mean war with Mexico. Andrew Jackson, the terminally ill Democratic patriarch, rejected the presumptive Democratic nominee Martin Van Buren over Van Buren's opposition to annexation and summoned James K. Polk, a former Tennessee congressman and House Speaker, anointing the relatively unknown politician as a pro-annexation alternative. Greenberg details Polk's compensating work ethic and his political partnership with his wife, Sarah Childress Polk, who served as his closest advisor, read and marked all newspapers for him, and managed their political relationships. At the fractured Democratic convention, Polk became America's first dark-horse nominee on the ninth ballot. His campaign centered on territorial expansion, while Clay hedged on Texas with contradictory letters that undermined his credibility. Lincoln campaigned vigorously for Clay across Illinois. Polk won by a razor-thin margin, and Congress passed a joint resolution annexing Texas in early 1845.

Polk entered office with a secret goal, shared only with Sarah: acquiring California from Mexico. He dispatched an envoy on a deliberately provocative diplomatic mission to purchase California, but the mission was designed to fail, and Mexico refused to receive the envoy. Polk then ordered General Zachary Taylor to march 4,000 troops to the Rio Grande, deep into territory claimed by Mexico. Colonel Ethan Allen Hitchcock, one of Taylor's officers, wrote of the march, "We have not one particle of right to be here." When Mexican cavalry crossed the river and clashed with a U.S. patrol in April 1846, killing 11 soldiers, Polk drafted a war message falsely claiming Mexico had "invaded our territory and shed American blood upon the American soil." Democratic leaders bundled his declaration with a troop-funding bill and stifled debate, forcing Congress to choose between endorsing Polk's falsehoods and appearing to abandon soldiers under fire. Only 14 representatives, led by the elderly John Quincy Adams, voted against the measure.

Volunteers flooded enlistment offices. Hardin, whose great-grandfather had been a Revolutionary War hero, became the first man in Illinois to enlist. Lincoln's friend Edward Baker also volunteered, leaving Lincoln as the only prominent Whig in the district who did not go to war. Lincoln chose instead to pursue his congressional campaign, guided by a Whig philosophy that self-improvement mattered more than territorial conquest. Taylor's forces won dramatic victories at Palo Alto, Resaca de la Palma, and Monterrey, and newspapers celebrated the general as a hero. Greenberg also highlights the presence of enslaved African Americans who accompanied officers to Mexico as personal servants, figures rendered invisible in public accounts of the war.

As the occupation continued, reports of volunteer atrocities against Mexican civilians appeared in newspapers. Murders, robberies, and rapes were committed with near-impunity, particularly by Texas Rangers and Arkansas volunteers. Hardin, camped in northern Mexico without seeing action, grew disillusioned, now doubting "whether it is worth it" to annex Mexican territory. The war's toll became starkly personal at the Battle of Buena Vista in February 1847. Polk had stripped Taylor of most veteran troops for General Winfield Scott's invasion of central Mexico and had allowed the exiled Mexican general Antonio López de Santa Anna to return from Cuba, mistakenly believing Santa Anna would negotiate peace. Instead, Santa Anna raised an army of 20,000 and marched north. Hardin led a charge that blundered into Santa Anna's main assault and was killed by Mexican lancers. Henry Clay Jr., a lieutenant colonel of Kentucky volunteers, was shot and bayoneted during the same retreat. Both became national martyrs. Clay learned of his son's death at his Kentucky estate, Ashland, and sought solace in religion.

Scott's army stormed Veracruz in March 1847, bombarding the walled city for 48 hours and killing hundreds of civilians, while embedded journalists reported the carnage in unprecedented detail. Polk dispatched Trist to Mexico with a secret peace treaty; Trist and Scott initially clashed but reconciled and became allies in the cause of peace. The antiwar movement gathered force through 1847: Enlistment declined, returning volunteers appeared physically and morally degraded, and the Wilmot Proviso, a congressional amendment banning slavery from conquered territory, passed the House twice. Hardin's funeral in Jacksonville, Illinois, drew 15,000 people, including Lincoln, and the eulogist openly questioned whether the war justified its cost. Scott fought his way to Mexico City through a series of battles and entered the capital on September 14, 1847.

That November, Clay delivered his Lexington address, a two-and-a-half-hour speech condemning Polk for provoking an "unnecessary" war, mourning the dead, and opposing the extension of slavery into new territory. Lincoln, visiting his wife's family in Lexington, heard the speech in person. Greenberg argues the address transformed Lincoln's political mission, convincing him that opposing the war and the spread of slavery must take precedence over economic issues. Clay's speech ignited antiwar rallies across the country, though it damaged his standing among southern Whigs and effectively ended his presidential ambitions.

When the Thirtieth Congress convened in December 1847, Lincoln delivered his Spot Resolutions, demanding that Polk identify the exact spot where American blood had been shed on American soil. In January 1848 he gave a full speech calling Polk a liar seduced by "military glory, that attractive rainbow, that rises in showers of blood." Illinois Democrats labeled him "Ranchero Spotty," but Lincoln refused to back down, voting to declare the war unconstitutionally begun by the president and supporting both the Wilmot Proviso and a bill to abolish slavery in Washington, D.C.

In Mexico, Trist received Polk's recall order but refused to return, convinced the war was unjust and that he alone could negotiate peace before Polk's growing ambitions dismembered Mexico entirely. On February 2, 1848, Trist and the Mexican commissioners signed the Treaty of Guadalupe Hidalgo, which ceded Alta California and New Mexico to the United States, recognized the Rio Grande as the Texas border, and provided for a payment of 15 million dollars. Trist later wrote that his "feeling of shame as an American was far stronger" than the Mexicans' humiliation. Polk reluctantly accepted the treaty, recognizing that the Whig-controlled Congress would refuse further war funding if he rejected it.

Greenberg assesses the personal toll on each central figure. Clay sacrificed his presidential ambitions by speaking against the war. Lincoln was spurned by his constituents and retired from Congress after a single term. Trist was fired and spent two decades in poverty. Hardin was killed leading a strategically pointless charge. Polk died three months after leaving office. In the epilogue, Greenberg follows Hardin's daughter Ellen Hardin Walworth, who in 1890 co-founded the Daughters of the American Revolution (DAR) with three other women. The DAR required proven descent from a patriot of the American Revolution. Ellen's founding application cited not her father but her great-grandfather, the Revolutionary War hero. Sarah Polk, then 87, accepted a position as honorary vice president. Greenberg notes that the U.S.-Mexican War has no monument in Washington, D.C., while the DAR headquarters stands two blocks from the White House, a physical testament to the nation's preference for remembering wars of liberation over wars of conquest.