In the decade just before the American Civil War, an anti-Black law was adopted in the state, which made it difficult for new Black emigrants to enter or live in Illinois.
[4] After an unsuccessful attempt at lead mining, Renault founded St. Philippe, Illinois, in 1723, and used his enslaved people for agricultural purposes to produce crops.
The institution of slavery continued after Britain acquired the eastern Illinois Country in 1763 following the French and Indian War.
[1] Slaveowners could keep their workers in bondage by forcing them to sign indentures of very long length (40 to 99 years), threatening them with sale elsewhere if they refused.
[6] The Illinois Salines, a U.S. government-run salt works near Shawneetown was one of the largest businesses in the Illinois Territory; it exploited between 1,000 and 2,000 slaves hired out from masters in slave states (primarily Kentucky) to keep the salt brine kettles continuously boiling.
However, due to the efforts of a coalition of religious leaders (Morris Birkbeck, Peter Cartwright, James Lemen, and John Mason Peck), publisher Hooper Warren and politicians (especially Edward Coles, Daniel Pope Cook and Risdon Moore), Illinois voters in 1824 rejected a proposal for a new constitutional convention that could have made slavery legal outright.
[7][8] Slavecatchers from Missouri would travel to Illinois either to recapture escaped slaves, or kidnap free blacks for sale into slavery, particularly since Illinois' legislature tightened the Black Code to state that recaptured escaped slaves would have time added to their indentures.
In Choisser v. Hargrave, the court decided that indentures would not be enforced unless they complied with all provisions of Illinois law, including that they be registered within 30 days of entering the state.
Illinois residents participated in the Underground Railroad for fugitive slaves seeking freedom, with major routes beginning in the Mississippi River towns of Chester, Alton and Quincy, to Chicago, and lesser routes from Cairo to Springfield, Illinois or up the banks of the Wabash River.
Subsequent legislation, however, led to one of the most restrictive Black Code systems in the nation until the American Civil War.