Dews Family Genealogy Forum
Since my Dews line is from Chicago, and before that, Yorkshire, England, I have no specific information about African-American Dews families except that I know many are from Arkansas. My dad worked with a man from Texarkana named Johnnie Dews, who was African-American and whose ancestors were from Arkansas. Also, thirty-five or more years ago my parents were paid a visit by two elderly sisters from Oklahoma, both white women, who said their father or grandfather had a farm in Arkansas and owned slaves there.
Hope these tidbits help your search. Are you using Census records?