On May 13, 1846, President James K. Polk went to Congress and asked it to declare war on the Mexican state. Congress responded with an emphatic “Yes” vote, House voting 174-14 and the Senate voting 40-2. The war ended with Mexico ceding just over one-third of its territory to the United States in February of 1848.
The American political scene in 1846. The Mexican-American War was fought at a time when Andrew Jackson’s Democratic Party was at odds with the Whig Party, which had echoes of the old Federalist Party in it, but was mostly an anti-Jacksonian party that was popular from the 1840s-60s, when it fell apart and the GOP emerged to challenge the Democrats. At the time of Polk’s request for a declaration of war, the Whigs from the northeast were vehemently anti-war, arguing that acquiring Mexican territory would create more votes in Congress for slaveholders, who voted reliably for Democrats. The war itself was unpopular at first, as it was the first war against an internationally-recognized state in 30 years (the U.S. had done plenty of fighting in between the War of 1812 and the Mexican-American War, but it was against polities that went unrecognized in the international arena, like Native American confederacies, Mediterranean principalities, or southeast Asian sultanates).
Mexican political scene in 1846. The Civil War in the United States was only 15 years away, so the situation in the U.S. was tense and volatile, but the Mexican political scene was even worse. In 1829, a mere eight years after Mexico won its independence from Spain, the latter attempted to reconquer and reclaim its former colony, resulting in a devastating war that further fractured the fledgling republic. (Mexico was not entirely blameless. In 1826, it tried to invade Spain-held Cuba as a way to set up an overseas empire of its own.) Ideologically, the country largely mirrored its northern foe, with one faction wanting a strong, centralized federal government to guide the economy into the industrial way of life, and the other faction wanting a weaker central government and protections for the agricultural way of life. Mexico had the added burden, though, of a third ideologically distinct faction: monarchists. While monarchists in the U.S. simply fled to Canada, or adapted to their circumstances, monarchists in Mexico remained strong enough to mount legitimate political campaigns in Mexico City.
Native American political scene in 1846. There are four Indian nations that played a major role in the Mexican-American War: Comanche, Navajo, Apache, and Maya (in Yucatán). When Spain lorded over its New World colony it had a two-pronged foreign policy for Native Americans on its northern frontier: build missions and trade goods for peace. This policy worked well enough for centuries, but when Mexico assumed its position as an independent republic, the northern frontier began to bleed, as the Comanche (check out Pekka Hämäläinen’s 2009 book, The Comanche Empire), Navajo, and Apache began violently carving out spheres of influence in what had rapidly become a free-for-all zone. The American government was much more efficient at fighting stateless enemies than was Mexico (thanks to its excursions in Asia, the Mediterranean, and Native America), so much so that the Spanish-speaking, Catholic inhabitants of Mexico’s northern frontier area lobbied for an American presence in the region. Washington, seeking to expand its territory to the Pacific Ocean, obliged.
At the southernmost end of the Mexican republic was another frontier, this one being more densely populated than Mexico’s northern frontier and more politically and economically connected to Mexico City. That didn’t stop Yucatán from attempting to break away from Mexico and form its own republic, however. In 1841, a secession-minded Yucatán faction declared the peninsula’s independence from Mexico (Texas did the same in 1835), and, just as with Texas, Mexico refused to recognize it. A violent Maya uprising against the Yucatán republic began just as the Mexican-American War heated up. Things got so bad that Yucatán’s elite petitioned Washington to annex their republic, and while President Polk and a number of other expansionists (such as Jefferson Davis, then a Senator of Mississippi) were pleased to do so, the annexation failed to pass through Congress (the House passed it, but the Senate killed the idea, citing unforeseen costs associated with putting down a Maya rebellion).
Texas. In 1821, the newly-established Mexican government was having severe trouble with the Comanche in the area and invited Americans to settle the region. This pushed the Comanche west and helped weaken them, but it also laid the groundwork for a Texian secession from Mexico. Texas declared independence from Mexico in 1835, but of course nobody in Mexico City recognized this declaration. Texas and Mexico fought for more than a decade before representatives from the Lone Star Republic finally succeeded in lobbying Washington to annex Texas and incorporate it into the American federation. It’s worth noting here that immigration was not the cause of Texian secession from Mexico, as some nativists are apt to claim today. Texas was, like Yucatán, tired of being governed poorly from Mexico City. The anti-immigration argument would be much stronger if Mexico wasn’t facing revolts and secessions everywhere it turned.
Next week will be more on the Mexican-American War, with a focus on the issue of slavery. It was so contentious, and so important, that it’s worth an entire post of its own. Stay tuned!