Missouri Compromise 1820: In an effort to preserve the balance of power in Congress between slave and free states, the Missouri Compromise was passed in 1820 admitting Missouri as a slave state and Maine as a free state.
Compromise of 1850: The Compromise of 1850 consists of five laws passed in September of 1850 that dealt with the issue of slavery. In 1849 California requested permission to enter the Union as a free state, potentially upsetting the balance between the free and slave states in the U.S. Senate. Senator Henry Clay introduced a series of resolutions on January 29, 1850, in an attempt to seek a compromise and avert a crisis between North and South. As part of the Compromise of 1850, the Fugitive Slave Act was amended and the slave trade in Washington, D.C., was abolished. Furthermore, California entered the Union as a free state and a territorial government was created in Utah. In addition, an act was passed settling a boundary dispute between Texas and New Mexico that also established a territorial government in New Mexico.
Fugitive Slave Act: The Fugitive Slave Acts were a pair of federal laws that allowed for the capture and return of runaway slaves within the territory of the United States. Enacted by Congress in 1793, the first Fugitive Slave Act authorized local governments to seize and return escaped slaves to their owners and imposed penalties on anyone who aided in their flight. Widespread resistance to the 1793 law later led to the passage of the Fugitive Slave Act of 1850, which added further provisions regarding runaways and levied even harsher punishments for interfering in their capture.
Kansas Nebraska Act (1854): The Kansas-Nebraska Act was an 1854 bill that mandated “popular sovereignty”–allowing settlers of a territory to decide whether slavery would be allowed within a new state’s borders. Proposed by Stephen A. Douglas (Abraham Lincoln’s opponent) the bill overturned the Missouri Compromise’s use of latitude as the boundary between slave and free territory. The conflicts that arose between pro-slavery and anti-slavery settlers in the aftermath of the act’s passage led to the period of violence known as Bleeding Kansas, and helped paved the way for the American Civil War.
Dred Scott vs. Sanford (1857): Also know as the Dred Scott decision, this was a legal case in which the U.S. Supreme Court on March 6, 1857 that a slave (Dred Scott) who had resided in a free state and territory (where slavery was prohibited) was not entitled to his freedom; and that African Americans were not and could never be citizens of the United States; and that the Missouri Compromise (1820), which had declared free all territories west of Missouri and north of latitude 36°30′, was unconstitutional. The decision added fuel to the sectional controversy and pushed the country closer to civil war.