I found this article while searching on something totally different. This gives the history of the Amos and Andy characters. You have to go down the page to the right article.)
Brother Gos and Brother Charlie
The Story of Amos 'n' Andy
by Sir Knight Peter H. Johnson, Jr., P.G.C. of Arizona
http://knightstemplar.org/KnightTemplar/0607.html#1806