- The admission of new states to the Union became tied to the issue of slavery, with a balance being maintained between slave and free states until the 1840s. However, this balance was upset with the annexation of Texas and the Mexican-American War (1846-1848), which resulted in the acquisition of vast new territories in the Southwest.
- The Compromise of 1850 temporarily resolved the issue of slavery in the new territories, but tensions between the North and South grew due to differences over issues such as the Fugitive Slave Act and the Kansas-Nebraska Act.
- The Dred Scott decision in 1857, which denied citizenship to all African Americans regardless of their status as free or slave, further inflamed tensions and played a major role in bringing on the Civil War.
Economic Factors
- The economies of the North and South were increasingly diverging. The North was increasingly becoming an industrial economy, while the South was more agricultural and reliant on cotton production. This created economic competition between the regions, as well as different interests in tariffs and government policies related to economic development.
-The Southern economy also depended heavily on slavery, which was increasingly seen as morally wrong in the North.
Social Factors
- Social attitudes towards slavery played a major role in dividing the North and South. Slavery was widely accepted and considered necessary for the Southern economy, while in the North there was a growing movement to abolish it. This led to deep social and cultural divisions between the two regions.
-The election of Abraham Lincoln, a Republican opposed to slavery, in 1860 led the Southern states to secede from the Union, leading to the outbreak of the Civil War.