Texas, Annexation, and the Election of 1844

American settlers moved into Mexican Texas through the 1820s and 1830s, most bringing enslaved labor and cotton farming with them. Tensions with the Mexican government over slavery, religion, and autonomy boiled over into revolt, and Texans declared independence in 1836, winning it after defeating Santa Anna's army at San Jacinto. Texas immediately asked to join the United States. Washington stalled. Texas would enter as one enormous slave state, big enough to eventually be carved into several more, and that threatened to wreck the careful balance of free and slave states in the Senate. Annexation also meant likely war with Mexico, which still considered Texas a rebellious province. For nine years, Texas existed as an independent republic while American leaders avoided the question.

By 1844 expansion had become impossible to dodge. James K. Polk ran as an unapologetic expansionist, promising both Texas annexation and the acquisition of Oregon, framing growth as the nation's destiny. His opponent hedged on Texas, wary of the slavery question. Polk won narrowly, and that result told politicians something real: enough voters wanted expansion that a candidate could ride it into the White House. Congress annexed Texas shortly before Polk took office.

Texas's entry as a slave state immediately upset the balance Congress had tried to protect since the Missouri Compromise, and it helped trigger the Mexican-American War, which in turn reopened the whole question of slavery in new territories that the next units track closely.