The document summarizes several key events that increased sectional tensions between the North and South leading up to the Civil War. These include the Missouri Compromise of 1820, which banned slavery in new territories north of 36°30′ latitude; the Treaty of Guadalupe Hidalgo in 1848, which ceded large territories to the US after the Mexican-American War; and the Kansas-Nebraska Act of 1854, which repealed the Missouri Compromise and allowed territories to decide the slavery issue themselves through popular sovereignty.