Westward Expansion and the Mexican War HIS 103

Trails to the West  Mexico loosely controlled northern provinces  John Frémont & Kit Carson explored Rockies in 1840s  Oregon Country jointly ruled by Britain & U.S.  Buchanan-Pakenham Treaty (1846) divided Oregon in half at 49 th parallel Copyright 2000, Bedford/St. Martin’s Press

Manifest Destiny  Coined by N.Y. journalist John O’Sullivan in 1845  Symbolized belief that superior white, Christian civilization was destined to rule continent  Jackson’s Indian removal policy meant to clear the way for this  Ft. Laramie Conference (1851) began process of confining Plains Indians to reservations American Progress, by John Gast (1872)

The Lone Star Republic  Adams-Onís Treaty (1819) settled boundary with Mexico & added Florida  Mexico permitted American settlement,  Organized by empresarios like Stephen Austin  20,000 Americans in Texas by 1830  Gen. Antonio Lopez de Santa Anna became dictator of Mexico in 1834  Sam Houston led Texas Revolution in 1836  The Alamo (Feb. 23 – March 6, 1836) & Goliad Massacre (March 20) spurred rebels  Santa Anna captured at San Jacinto (April 21) & forced to grant Texas independence Copyright 2000, Bedford/St. Martin’s Press The Alamo

San Jacinto MonumentAntonio Lopez de Santa Anna

Annexing Texas  Jackson tried to buy all of northern Mexico in 1835, but refused to submit annexation treaty in 1836  John Quincy Adams staged 3-week filibuster in 1838 to prevent annexation  1844 annexation treaty defeated when Secretary of State John Calhoun explicitly linked it to defense & expansion of slavery  Became key issue in 1844 campaign  James Polk demanded Oregon & Texas  Henry Clay backpedaled at last minute, costing him N.Y. & election  Lame-duck Congress passed joint resolution annexing Texas in 1845 Sam Houston

Polk Provokes a War  John Slidell sent to Mexico, Dec  Offered $25 million for California, New Mexico & territory north of Rio Grande  Rejected by resentful Mexican gov’t  Polk ordered Gen. Zachary Taylor’s troops to north bank of Rio Grande  Nueces River was boundary  Claimed “American blood shed on American soil”  Whigs opposed war, but voted to fund it to show patriotism

The Mexican War ( )  Taylor’s army won battles of Monterrey (Sept. 1846) & Buena Vista (Feb. 1847)  Winfield Scott led amphibious invasion that captured Mexico City in Sept  John Frémont & Stephen Kearny conquered California & New Mexico Copyright 2000, Bedford/St. Martin’s Press

Battle of Monterrey (Sept. 1846)

Gen. Scott Enters Mexico City

The Results  The cost of war:  12,876 U.S. soldiers dead  $98 million  Junior officers became Civil War generals  Treaty of Guadeloupe Hidalgo (1848):  U.S. acquired California, New Mexico & rest of Texas (over 500,000 square miles)  75,000 inhabitants would become U.S. citizens if they chose to stay  U.S. paid Mexico $15 million & assumed $3.25 million in U.S. citizens’ claims against Mexico Gen. Zachary Taylor Gen. Winfield Scott

War Politicized Slavery Issue  Wilmot Proviso  David Wilmot was a Pennsylvania Democrat  Banned slavery in all territories acquired from Mexico  Calhoun Resolutions  John C. Calhoun argued territories were common possession of all states & citizens  Forbidding slave owners to bring slaves into territories violated 5 th Amendment  Popular Sovereignty  Lewis Cass was a Michigan Whig turned Democrat  Argued each territory should decide slavery issue for itself David Wilmot Lewis Cass