| A | B |
| Union | the United States as one nation united under a single government. During the Civil War, "the union" came to mean the government and armies of the North |
| Missouri Compromise | an agreement made by Congress in 1820 under which Missouri was admitted to the Union as a slave state and Maine was admitted as a free state |
| Fugitive | a person who flees or tries to escape |
| Wilmot Proviso | a proposal made in 1846 to prohibit slavery in the territory added to the United States as a result of the Mexican-American War |
| Compromise of 1850 | the agreements made in order to admit California into the Union as a free state. These agreements included allowing the New Mexico and Utah territories to decide whether to allow slaveryy, outlawing the slave trade in Washington, D.C., and creating a stronger fugitive slave law |
| Kansas-Nebraska Act | an act passed in 1854 the created the Kansas and Nebraska territories and abolished the Missouri Compromise by allowing settlers to determine whether slavery would be allowed in the new territories |
| Dred Scott decistion | a Supreme Court decision in 1857 that held that African Americans could nver be citizens of the United States and that the Missouri Compromise was unconstitutional |
| Lincoln-Douglas debates | a series of political debates between Abraham Lincoln and Stephen Douglas, who were candidates in the Illinois race for U.S. senator, in which slavery was the main issue |