There are a number of books, articles, dissertations that deal with free people of color, including my own dissertation that deals with free people of color in Mobile, Alabama. (That project has been expanded to include Baldwin County. ) If you are interested in Alabama, several articles by Gary Mills are available at the library. There are excellant studies dealing with Louisiana, especially New Orleans and the area around St. Landry Parish. Free blacks worked in a variety of ways, skilled and unskilled positions. Some owned a lot of property, including slaves, and produced a number of different crops. (Black Masters is the title of another book that traces the lives of a free black family in South Carolina. )