Belleville’s German heritage intersects the African American story of Illinois quite significantly because the German (“Latin Farmers”) immigrants were fervent abolitionists. In an area outside Belleville known as Shiloh Valley and Turkey Hill these Germans protected freed (and, presumably, escaped) slaves.
One of the primary black families in Belleville, the Freemans, came to Illinois in 1818 as enslaved or indentured people but were manumitted as soon as they got to St Clair County. They had a large farm in Shiloh Valley, complete with a school marked on 19th-century maps as the “African School.” This, along with the cemetery (see banner image above), is located at the edge of a forest preserve today.
The Belleville News-Democrat has a fascinating story by Teri Maddox about the free African American community of Belleville in the February 26, 2017 issue. See: https://www.bnd.com/living/magazine/article135074699.html