The Missouri Compromise was a federal legislation of the United States that balanced desires of northern states to prevent expansion of slavery in the country with those of southern states to expand it.

Protective tariffs are taxes, dues, or fees placed on foreign goods. They are a tool countries use to protect domestic industries by reducing competition from international businesses.

The Nullification Crisis was a result of southern states resistance to imposed, protective tariffs on foreign goods to guard emerging industries. Southern states viewed these tariffs as “unconstitutional”.

The Mexican–American War, also known in the United States as the Mexican War, was an invasion of Mexico by the United States Army from 1846 to 1848. It followed the 1845 American annexation of Texas, which Mexico still considered its territory because Mexico refused to recognize the Treaties of Velasco.

California being admitted as a free state and the borders of Texas being settled, with areas ceded by Texas becoming the recognized territories of New Mexico and Utah.

the struggles of a slave, Tom, who has been sold numerous times and has to endure physical brutality by slave drivers and his masters.

repealed the Missouri Compromise, created two new territories, and allowed for popular sovereignty.

Three distinct political groups occupied Kansas: pro-slavery, Free-Staters and abolitionists. Violence broke out immediately between these opposing factions and continued until 1861 when Kansas entered the Union as a free state on January 29. This era became forever known as Bleeding Kansas

the U.S. Supreme Court stated that enslaved people were not citizens of the United States and, therefore, could not expect any protection from the federal government or the courts.

John Brown and several followers seized the United States Armory and Arsenal at Harpers Ferry. The actions of Brown's men brought national attention to the emotional divisions concerning slavery.

Lincoln won the Electoral College with less than 40 percent of the popular vote nationwide by carrying states above the Mason–Dixon line and north of the Ohio River, plus the states of California and Oregon in the Far West. Unlike every preceding president-elect, Lincoln did not carry even one slave state.

The victory of Abraham Lincoln in the 1860 presidential election triggered cries for disunion across the slaveholding South.