Pre-Civil War Timeline

Invention of the cotton gin

1794

The cotton gin was invented in 1794 by Eli Whitney.This machine greatly increased the speed of removing seeds from the cotton fiber. By the mid 19th century cotton was America's leading export.
http://www.history.com/topics/inventions/cotton-gin-and-eli-whitney

Missouri Compromise

1820

In 1819 the pro-slavery and anti-slavery factions began to tense and cause problems in the U.S. this lead congress to pass the Missouri Compromise to keep peace. This was an imaginary line that went across the Louisiana territory.
http://www.history.com/topics/missouri-compromise

Tariff of 1828 & Nullification Crisis

1828