| A | B |
| Missouri Compromise | Political agreement that settled the status of slavery in the Louisiana Territory. Maine was admitted to the Union as a free state; Missouri as a slave state; and slavery was prohibited in any other territory north of the 36' 30" line of latitude. |
| James K. Polk | 11th President of the United States; known for his "manifest destiny" approach to westward expansion. |
| Manifest Destiny | A notion held by nineteenth-century Americans that the United States was destined (by God) to rule the continent; from the Atlantic the Pacific. |
| Mexican War (1846-1848) | 1846 war between the United States and Mexico during which the United States acquired much of the present-day Southwest from Mexico. |
| Sectionalism | loyalty to one's own region or section of the country; rather than to the country as a whole. |
| Compromise of 1850 | A series of 5 laws; the purpose of which was to settle the status of slavery in California and settle other divisive issues between North and South. |
| Kansas-Nebraska Act | 1854 - Created Nebraska and Kansas as states and gave the people in those territories the right to chose to be a free or slave state through popular sovereignty. |
| Popular Sovereignty | To let the voters decide the status of slavery in a given territory instead of Congress. |
| Scott v. Sanford | The 1857 Supreme Court decision ruling that a slave who had escaped to a free state enjoyed no rights as a citizen and that Congress had no authority to ban slavery in the territories. |
| John Brown's Raid | In 1859; a militant abolitionist seized the U.S. arsenal at Harper's Ferry. He planned to end slavery by massacring slave owners and freeing their slaves. He was captured and executed. |
| Election of 1860 | Lincoln; the Republican candidate; won because the Democratic party was split over slavery. As a result; the South no longer felt like it has a voice in politics and a number of states seceded from the Union. |
| Oregon Trail | Pioneer trail that began in Missouri and crossed the great plains into the Oregon country |
| 36° 30' line | According to the Missouri Compromise (1820); slavery was forbidden in the Louisiana territory north of the a certain latitude. This was nullified by the Kansas-Nebraska Act. |
| Treaty of Guadalupe Hidalgo | Treaty that ended the Mexican War; granting the U.S. control of Texas; New Mexico; and California in exchange for $15 million |
| Wilmot Proviso | Bill that would ban slavery in the territories acquired after the War with Mexico |
| Mexican Cession | Lands sold by Mexico to the US following the Mexican War |
| Bleeding Kansas | A sequence of violent events involving abolitionists and pro-Slavery elements that took place in Kansas-Nebraska Territory. The dispute further strained the relations of the North and South; making civil war imminent. |
| Secession | the formal withdrawal of a state from the Union |