Content Warning: This section of the guide discusses enslavement and racism.

African were first enslaved and transported to North America by Spanish colonialists at the start of the 16th century. By the time the United States declared its independence from Britain in 1776, chattel slavery was legal in all 13 American colonies. However, shortly after gaining independence, the country became divided on slavery. Northern states began the process of emancipation, creating a division between free Northern states and slave-holding Southern states. Although the importation of new enslaved Africans was prohibited, the domestic trade of enslaved people continued to thrive, especially as Southern states relied on the labor of enslaved people to fuel the agriculture-based economy. Enslaved people in the South often lived in terrible conditions, were subject to violence, and were forcibly separated from their families. Many attempted to seek freedom in free states in the North. Although the Fugitive Slave Clause stated that self-liberated people must be returned to their former enslavers, many Northerners were sympathetic, and networks existed to support self-liberated people.

As the United States acquired more territories over the course of the 19th century, the proportion of free states and slaveholding states threatened to unbalance, and Southern states began to worry about losing their enslaved workforce.