I recently found in the 1850 census some of my ancestors-- a white family named Minkler who had living with them a 16-year-old african-American boy named "Charly Minkler." The parents were both born in New York, but Charlie was born in Massachusetts. The Minklers lived in Kendall, Illinois, not too far from Chicago. Underground Railroad route maps, I think, show that they might have gone right through this area...but I can't tell if this boy was born free in Massachusetts or why he would be so readily identified on the census as black when the Fugitive Slave Law was in effect (i.e even free-born African-Americans were in danger).

Any ideas about how I can investigate this further would be appreciated.