But she [America] goes not abroad, in search of monsters to destroy.… [Were she to do so] the fundamental maxims of her policy would insensibly change from liberty to force.… She might become the dictatress of the world.
— Secretary of State, John Quincy Adams (1821)
It was an odd peace, negotiated by a once-trusted, Democratic Party loyalist who, though appointed by Polk himself, soon turned against the war, defied his president, and — with the support of equally exasperated American generals — unilaterally negotiated an essential peace, despite knowing that doing so would destroy his own career. Few today have heard of Nicholas Trist — which was precisely James Polk’s intent. Nevertheless, the man — a bona fide American hero and man of impeccable integrity — should be celebrated, even now, in schools across the nation. Trist had an interesting background. He had married Thomas Jefferson’s granddaughter, lived for many years with the ex-president, and became his personal secretary, dear confidant, and — similar to Polk with Jackson — his protégé of sorts. The Jefferson connection undoubtedly influenced Trist’s professional life, most especially his troubled, courageous, mission to Mexico.
When Trist arrived on his secret peace mission in Mexico, General Scott was suspicious from the get-go. Long convinced that Polk planned to replace him with a Democratic Party loyalist-general, Scott saw Trist as a threat and rival. So contentious were their earliest interactions that Scott initially threatened to resign if Trist wasn’t recalled. Over time, however, Scott — increasingly desperate for a peace settlement — came to realize that Trist was his best hope. The two became friendly confidants, both eager for peace at almost any cost, and even sought to undermine the president’s increasingly ambitious, expansionist sentiments. Scott and Trist both recognized the precariousness of the American military situation, wherein a relatively small U.S. Army — deployed deep in the Mexican interior and harassed by guerrillas — was trapped in occupation duty with no end in sight.
Polk, too, trod on delicate ground. His Democratic loyalists had begun to call for the annexation of all of Mexico. Sam Houston, the former president of the Republic of Texas, had just proclaimed the entirety of the vanquished nation as the “birth-right” of the United States. “Assuredly as tomorrow’s sun will rise … so certain it appears to my mind,” he asserted, “must the Anglo-Saxon race pervade … throughout the whole rich empire of this great hemisphere.” Polk hoped for a quick peace that would gain the United States as much of Mexico as possible in order to placate the “All-Mexico movement” in his own party.
Thus, when Trist demonstrated his willingness to negotiate a somewhat more lenient, “just” peace with the provisional Mexican government, Polk decided to fire him. If Trist remained in place, Polk concluded at a hasty cabinet meeting held in his private bedroom, it might convince the Mexicans that “the U.S. were so anxious for peace that they would ultimately conclude one upon the Mexican terms.” Secretary Buchanan, who had once argued against any annexation of Mexican territory, now — with presidential ambitions of his own — declared the full annexation of Mexico was “that destiny which Providence may have in store for both countries.”
Meanwhile, down in Mexico itself, Scott and Trist had come to agree on the futility of a lengthy military occupation. Scott’s racial biases were on full display in his opposition to total annexation. “There are not more than one million,” out of eight million Mexicans, “who are of pure European blood. The Indians and the mixed races constitute about seven millions. They are exceedingly inferior to our own. As a love of my country, I was opposed to mixing up that race with our own.”
The longer he spent on the ground in Mexico, Trist’s view of the untenable American military situation, and the (aggressive) nature of the entire U.S. military invasion, changed. His country’s conquest of Mexico and occupation of its capital, he soon wrote, was a “thing for every right-minded American to be ashamed of.” Scott agreed, as much on tactical as moral grounds, and the two men collaborated to defy Polk’s recall of Trist, and — exploiting the slow nature of communications with Washington — as the special envoy decided, to make peace with “as little exacting as possible from Mexico.” When the military dictator, Santa Anna, fell from power and was replaced by an originally anti-war moderate, Manuel de la Peña, Trist saw an opportunity to negotiate a peace before Peña fell in an (expected) coup.
Thus, when Trist finally received his recall orders, he made a profound, even unheard of, decision: he refused to accept his firing or return home as ordered. In that, Trist had Scott’s support. The general, also defying a president for whom he had no love, encouraged Trist to “finish the good work he had begun.” So it was that Trist composed and sent Polk a 645-page letter explaining just why he refused to be relieved of duty. A prolonged U.S. military occupation, he wrote, constituted an “incalculable danger to every good principle, moral as well as political, which is cherished among us.”
Back in D.C., Polk, influenced by the all-Mexico expansionists within his party, was horrified by Trist’s intransigence. “There is,” between Scott and Trist, “a conspiracy to put the government at defiance and make a treaty of some sort.” Down in Mexico, both the general and the diplomat realized that time was short. Any day a new general might arrive with orders to relieve Scott and physically remove Trist from army headquarters. So in a last desperate gambit, Scott threatened provisional President Peña. If a peace agreement was not soon signed, the U.S. Army would march out into the countryside and resume hostilities upon the Mexican people. And so it was, on February 2, 1848, that a fired diplomat and an insubordinate general signed the Treaty of Guadalupe Hidalgo. Mexico ceded the northern third of its territory — everything that Polk had desired in his initial guidance to Trist (with the exception of Baja California). The United States promised — but ultimately failed to fulfill — recognition of Mexican property rights in the annexed territory, to provide residents therein a path to U.S. citizenship, and to protect them from Indian raids along the new border.
Trist took scant comfort in the eventual settlement. As he admitted to his family, “Could those Mexicans [at the peace table] 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.” Though he knew, as a result of his actions, that his political career was over, Trist felt he had done as right as possible by both his own country and vanquished Mexico — his “conscience as a man,” was clear. Polk was furious, and still pressured by expansionists in his own party, but, after lengthy cabinet discussions and personal reflection — and undoubtedly cowed by the growing national anti-war movement — decided he had no choice but to accept the peace treaty that he had.
Trist returned as a pariah. He lived out much of the rest of his life in nearly abject poverty, a man without a party, or a benefactor, but at peace with himself. He had done the right thing; had saved lives on both sides; and had chosen integrity over advancement. His punishment was penury. Still, while Trist had done all he felt he could for the Mexicans, the U.S. government, would ultimately abrogate key provisions of the treaty with Mexico — just as it would time and again with Indian tribes within its own borders. The real losers of the war turned out to be newly Hispanic-Americans and Indians within the annexed territory. Under the conditions of the Mexican Constitution of 1824, to which — by the treaty — the United States was statutorily obligated to adhere, all Mexicans, including Indians, were considered citizens. Still, for generations, Mexican-Americans and, especially Indians, were treated as second-class citizens or foreigners within the borders of the United States.
The new state of California didn’t recognize Mexican-Americans as citizens until 1870; New Mexico refused until 1912. For decades, Texas restricted the right to land ownership to whites. As for the Indians, most of whom lived in California, matters were far worse. Within a single decade, 1845–55, after California’s American governor, Peter Burnett, predicted a “war of extermination” would rage until “the Indian race becomes extinct,” the native population fell from 150,000 to 50,000. The former slave and abolitionist Frederick Douglass probably best expressed the nature of the eventual settlement: “They [the peacemakers] have succeeded in robbing Mexico of her territory, and are rejoicing for their success under the hypocritical pretense of a regard for peace.” And so they had.
The end of American “innocence” and the seeds of Civil War
The United States will conquer Mexico, but it will be as a man who swallowed the arsenic which brings him down in turn. Mexico will poison us.
— Ralph Waldo Emerson (1846)
James K. Polk’s worst nightmare came true in the election of 1848. To his credit, and almost singularly among American executives, Polk did indeed eschew a reelection campaign. Still, he was a sincere Democratic loyalist and had long feared that a Whig — particularly a popular Whig general — would succeed him. And that is precisely what happened. One of the two celebrity theater commanders of the war, Gen. Zachary Taylor, assumed office in early 1849. That the Whigs — a party literally formed and held together by sheer loathing of Andrew Jackson — turned to another general (from a war they opposed) in a bid to take back the White House, demonstrated both their political opportunism and the pervading star power of military commanders throughout U.S. history.
Polk left Washington after Taylor’s inauguration and trekked back to Tennessee. By then a broken man, Polk may not have led his armies from the front in Mexico, but the war can be said to have killed him anyway. A workaholic with few worldly vices — not even rest — Polk was dead just three months later. Nonetheless, while Polk is unlikely to top many historians’ lists of “great” presidents, he was undoubtedly one of the most successful. He had, for better or worse, fulfilled nearly every one of his campaign promises. He had helped annex Texas; negotiated most of the Oregon Territory away from the British; provoked and sold a war that made the Manifest Destiny dream of an America that spanned “from sea to shining sea” a reality; and he even stepped down after a single presidential term, as he had pledged. Few occupants of the White House, before or since, can claim as much.
Nevertheless, Polk’s wartime leadership set a number of rather dark precedents for the young nation — questionably constitutional criteria that far too many of his successors would follow, and follow still. His was the first American war waged against another republic — once thought an impossibility by the Founding Fathers and their contemporary Enlightenment thinkers — the first based upon an unassailable lie, and the first that a significant portion of the populace opposed. That pattern has continued. So has Polk’s expansion of executive power in foreign affairs. As the first to truly identify, believe in, and execute the fiction that the Article II commander-in-chief clause of the Constitution grants near unlimited powers to the president, Polk undoubtedly did much to irreversibly enlarge the dominion of the presidency. Without Polk’s early precedent-setting and what logically followed, it is difficult to imagine the contemporary and seamless conduct of unsanctioned “terror wars” by the three consecutive administrations of George W. Bush, Barack Obama, and Donald Trump.
The sheer scope and horror of the Mexican-American War was also something new for the young American Republic. Though the Revolution counted a greater number of battle deaths, more U.S. soldiers had died in Mexico, and far more than in the War of 1812, or even in all the Indian wars (1817–1890) combined. In fact, per capita, the Mexican-American War was the deadliest for U.S. soldiers in the nation’s history. One in ten of the Americans who went to Mexico died there — the vast majority from illness and disease. More than 12,500 American servicemen and at least 25,000 Mexicans (soldiers and civilians) died in the conflict. And it is telling that the Mexican-American War is one of the few major conflicts not commemorated in Washington D.C. Though the war cost the U.S. government nearly $100 million (some $3 billion in today’s dollars), most historians agree that the massive economic and social disruption of the war significantly set back and stunted the progress and growth of Mexico.
That the United States had aggressively dismantled its neighboring republic raised, and raises, a number of uncomfortable questions. Could the United States still claim national altruism and define itself positively compared with the British, and other monarchies and empires? Of course it couldn’t. Would American expansion stop at the Pacific? It would not. More urgently, would slavery expand into the annexed territories, and if it did, would that placate Southerners? The answers: some of it, and, absolutely not.
The question of slavery in the Mexican cession — and later legislation permitting the peculiar institution throughout the far West — would, within just thirteen years, tear the United States asunder. It did so, in part, owing to the sectional breakdown of the “second” party system in American history. There had, before the war, been northern and southern factions of both Whigs and Democrats. Afterwards, the parties quickly became almost completely regional: Northern for the former, Southern in the case of the latter.
The indefatigable lion of the Senate, Henry Clay tried to halt this sectional fragmentation. In an attempt to recreate his 1824 “Missouri Compromise,” he again worked out a tenuous deal between pro- and anti-slavery states in 1850. In hindsight, his fatally precarious “Compromise of 1850” never stood a chance. His first grand bargain had held firmly for 24 years; his encore, barely ten.
Abraham Lincoln wasn’t even around to observe his old idol attempt this last trick. His anti-war position almost certainly cost him his coveted congressional seat. Meanwhile, Henry Clay, perhaps the most famous American politician never to serve as president, died within two years, and was thus spared the pain of watching his final deal collapse. Nevertheless, by the 1856 presidential election, the Whig Party essentially ceased to exist — replaced by the far more overtly anti-slavery Republicans. Just four years later, against all odds, Lincoln would ascend to the White House at the head of that new party.
The undeniable nature of historical contingency aside, one must reflect in wonder at some of the implications inherent in an accurate accounting of the Mexican-American War. If Emerson was right — and it seems he was — that the conquest of Northern Mexico poisoned American politics, upset the delicate slave-state versus free-state balance, and eventually tore the union apart, consider the ramifications. It could be said that 180 pro-slavery, illegal immigrant rebels holed up in an old Spanish mission named the Alamo sacrificed themselves for what they’d claimed was “freedom,” but inadvertently caused an American Civil War. What’s more, that much bloodier war would paradoxically be commanded — on both sides — by generals who were veterans of the Mexico invasion, many of whom had doubts, if not downright regrets, about the war of their youth.
Wilder still, the careers of the presidents on both sides of the monumental civil conflict to come were veritably built by the earlier conflict. On the Confederate side, Jefferson Davis — a West Point graduate — had served as a colonel of the Mississippi Volunteers under the command of his former father-in-law (his first wife had died), Zachary Taylor. Before he had resigned from Congress to lead the regiment, however, he had opposed a hasty invasion, and lamented on the House floor, “Unfortunately, the opinion has gone forth that no politician dares to be the advocate of peace when the question of war is mooted. That will be an evil hour — the sand of our republic will be nearly run — when it shall be in the power of any demagogue, or fanatic, to raise a war-clamor, and control the legislation of the country.” He fought well in all the major battles in Northern Mexico and was shot through the foot. Six years after the conflict’s end, while serving as secretary of war under President Franklin Pierce — who had himself served as a volunteer brigadier general under Gen. Winfield Scott — Davis successfully pushed for a revision of the original treaty that further benefitted the U.S. invaders. In the Gadsden Purchase, Washington acquired some 30,000 square miles of present-day southern Arizona and New Mexico — including the city of Tucson — to facilitate a southern branch of the transcontinental railroad.
Conversely, the Civil War–era president of the United States, Abraham Lincoln, had made his name — and risked his career — with his virulent, principled anti-war stance in Congress. So it was that both sides of the Civil War would be led by generals who had doubted the morality and efficacy of the Mexican-American War as young officers, and by presidents who’d once outright opposed it.
How immensely all this alters the standard patriotic narrative! Think of the significance: an aggressive U.S. regime-change war of conquest in 1846 boomeranged east a little more than ten years later and resulted in the deaths of more than 500,000 Americans — more, perhaps, than all the nation’s other wars combined. The implications for America’s imperial present are astonishing.
Bibliographical note: This piece draws extensively on Amy S. Greenberg’s book, A Wicked War: Polk, Clay, Lincoln, and the 1846 U.S. Invasion of Mexico (2012); on sections of Daniel Walker Howe’s volume in the Oxford History of the United States, What Hath God Wrought: The Transformation of America, 1846–1848; my chapter on the Mexican-American War from the “American History for Truthdiggers” series; and my teaching notes and lectures from West Point. Interested readers should read Greenberg’s work in full for a broader and more in-depth treatment of this massively complex subject.
This article was originally published in the September 2020 edition of Future of Freedom.