According to Arthur Cole, Centennial History of Illinois: The Era of the Civil War, 1848-1870 (Springfield: Illinois Centennial Commission, 1919), Illinois state laws restricting immigration of Negroes and other persons of color were repealed in 1865.

Cole summarizes Illinois Black Laws as following --

1. Negroes and mulattoes not alllowed to come into the state.
2. All contracts with such negroes and mulattoes declared to be void.
3. Any person encouraging them to come, or giving them employment, to be fined from $10 to $500
4. Negroes and mulattoes not to be allowed to vote
5. No negro, or mulatto having even one-eighth part of negro blood, shall marry a white person.
6. Any person counseling or assisting such marriage shall be fined from $100 to $1,000, and the marriage to be void.
7. Negroes and mulattoes are not allowed to testify against white persons, or send their children to free schools with white children, or hold any office.

As noted below, in February 1863 officials of Carthage IL convicted six blacks of violating state laws and sold them into slavery.

http://dig.lib.niu.edu/civilwar/settlement.html

Is anyone familiar with particulars of the Carthage convictions? To whom were these people sold?