I'd like to suggest you get copies for each year from 1870-1930, the year black people had surnames used to when you think they died. Look at everybody in the neighborhood as well. Try to chart your family with a family on each census you find your people. Sometimes one of those neighbors marry into the family and you may find cousins names.
Ancestry.com has a 1940 and 1950 substitute census. I buy 3 month subscriptions at a time from ancestry and research it for all I can.