| Missouri compromise | Maine would be admitted to the Union as a free state, Missouri would be admitted as a slave state, and slavery would be prohibited in the northern part of the Louisiana Purchase except for Missouri. |
| Gadsden Purchase | Gave the southern parts of New Mexico and Arizona to the US and allowed a future railroad to be constructed entirely within its borders. |
| Compromise of 1850 | California admitted as a free state. |
| Popular sovereignty | Used to determine whether new states would enter as “slave” or “free”. |
| Fugitive Slave Act of 1850 | Allowed special government officials to arrest any person accused of being a runaway slave. |
| Kansas-Nebraska Act | Violence erupted and widespread fighting occurred throughout Kansas, also known as the “Bleeding Kansas” event. |
| Dred Scott v. Sanford (1857) | Supreme Court decided that no black, free or slave, could claim U.S. citizenship, and therefore blacks were unable to petition the court for their freedom. |
| Emergence of Political Parties | Free-Soil Party (1848) and the Republican Party (1854) strongly opposed the spread of slavery to the West. |
| Presidential Election of Abraham Lincoln | Events moved quite rapidly once Lincoln was elected. South Carolina called for a convention to secede from the Union. Within three months of Lincoln’s election, seven states had seceded from the Union. |
| Contributions of minority groups | Contributions of women and African Americans, including the importance of the American Red Cross and Emancipation Proclamation. |
| Unintended Consequences | Destruction on the home front, print media and photography, technological advancements, and environmental impact |
