How did U.S. expansion create controversy?

Northern economy vs. Southern economy During the 1800s, slavery expanded in the South rather than the North because the geographic conditions of the South encouraged plantations. Northern economy vs. Southern economy

As the U.S. acquired more land, controversy over these territories focused on the extension of slavery.

Southerners wanted slavery extended to the West in order to keep enough strength in the U.S. Senate to protect Southern interests.

Congress attempted to solve the extension of slavery through a series of laws, such as: Senator Henry Clay of Kentucky

1. Missouri Compromise: banned slavery north of 36°30’ line.

2. Compromise of 1850: created five separate laws aimed at favoring both the North and South. Fugitive Slave Act of 1850 

3. Kansas-Nebraska Act: allowed the legalization of slavery in new states to be decided by popular sovereignty (voting). “Bleeding Kansas”

The controversy surrounding the extension of slavery eventually led to the start of the Civil War for the U.S.