The deadlock of territorial expansion along the Missouri Compromise line (1836-1848)

Résumé du document

The 1840s are associated with expansionism because this is the decade in which all arguments combined to justify a "land hunger" which had only been increasing since the beginnings of the American republic.
Agrarian Democrats saw the West as an antidote to urbanization and industrialization ; enterprising Whigs (especially in the N) looked to the new commercial opportunities of the West.

Extraits

[...] President Van Buren (1836-1840) ignored annexation. So Texans began to talk about developing ties with GB and extending their republic to the Pacific Coast. Pdt Tyler proslavery Whig, elected in 1840) believed this and began to fear for the preservation of American independence. He was also committed to expansion and hoped to build wider political support for his party by enlarging the area of slavery. But the Senate rejected the treaty of annexation, so for the time being the Pdt could not go any further. [...]

[...] The war was even carried into the heart of the Mexican territory, as far south as Vera Cruz (see map). Mexico City was finally captured in 1847, putting an end to the war. Representatives of both countries signed the Treaty of Guadalupe Hidalgo in February 1848, by which the USA gained CA and New Mexico (including present- day Nevada, Utah and Arizona) and recognition of the Rio Grande as the southern boundary of TX. In return, the US government agreed to settle the claims of its citizens against Mexico and to pay Mexico a mere $15 million. [...]

[...] The new pdt was determined to acquire California and the SW, and desired Oregon as well. His campaign supporters had threatened war with GB to gain all the Oregon Territory, but Pdt Polk had enough with the prospect of an impending war with Mexico. The Mexican-American War (1845-1848) With Mexico, Polk was much less diplomatic. He ordered the US troops to defend the border claimed by TX and contested by Mexico, and at the same time attempted to buy from the angry Mexicans a huge tract of land in the Southwest. [...]

[...] GB and the US had jointly occupied the Oregon Territory since 1818. The US had tried to fix the boundary between Canada and the USA at the 49th parallel (the present-day border) in the 1820s, but GB had refused to settle the question. The status quo had remained until the Cincinnati Convention of expansionists met in 1843 to demand the entire Oregon territory for the US, up to its northernmost border of 54°40' (including present-day British Columbia). They meant to lobby in Washington and push for a war in case GB refused such an arrangement. [...]

[...] At the Alamo mission in San Antonio in 1836, fewer than 200 Texans of both origins made a heroic stand against 3,000 Mexican soldiers led by General Antonio López de Santa Anna. When all the defenders of the fort (including Davy Crockett) died in the battle, ‘Remember the Alamo' became the rallying cry of the Texan rebels. A few months later, Sam Houston's victory over Santa Anna in the battle of San Jacinto gained Texas its independence. TX established a Lone Star republic but immediately sought annexation to the USA. [...]