Key Terms

alcalde

a Mexican official who often served as combined civil administrator, judge, and law enforcement officer

Barnburners

northern Democrats loyal to Martin Van Buren who opposed the extension of slavery into the territories and broke away from the main party when it nominated a pro-popular sovereignty candidate

Californios

Mexican residents of California

Compromise of 1850

five separate laws passed by Congress in September 1850 to resolve issues stemming from the Mexican Cession and the sectional crisis

Corps of Discovery

the group led by Meriwether Lewis and William Clark on the expedition to explore and map the territory acquired in the Louisiana Purchase

empresario

a person who brought new settlers to Texas in exchange for a grant of land

filibuster

a person who engages in an unofficial military operation intended to seize land from foreign countries or foment revolution there

forty-niners

the nickname for those who traveled to California in 1849 in hopes of finding gold

Free-Soil Party

a political party that sought to exclude slavery from the western territories, leaving these areas open for settlement by White farmers and ensuring that White laborers would not have to compete with enslaved labor

Liberty Party

a political party formed in 1840 by those who believed political measures were the best means by which abolition could be accomplished

Mexican Cession

the lands west of the Rio Grande ceded to the United States by Mexico in 1848, including California, Arizona, New Mexico, Nevada, Utah, and parts of Wyoming and Colorado

Missouri Compromise

an agreement reached in Congress in 1820 that allowed Missouri to enter the Union as a slave state, brought Maine into the Union as a free state, and prohibited slavery north of 36° 30′ latitude

Northwest Passage

the nonexistent all-water route across the North American continent sought by European and American explorers

Slave Power

a term northerners used to describe the disproportionate influence that they felt elite southern slaveholders wielded in both domestic and international affairs

Tallmadge Amendment

an amendment (which did not pass) proposed by representative James Tallmadge in 1819 that called for Missouri to be admitted as a free state and for all enslaved people there to be gradually emancipated

Tejanos

Mexican residents of Texas

Wilmot Proviso

an amendment to a revenue bill that would have barred slavery from all the territory acquired from Mexico