Green’s Dictionary of Slang

(US black) an African-American male.

1941		D. Burley N.Y. Amsterdam Star-News 17 May 11: The only sploes left on the main beat are the ones who scarfed chalk to make their tickers beat faster.
1946		D. Burley N.Y. Amsterdam News 27 July 17: ‘Marse Cholly’ [is] putting his foot sown harder on Splo’s neck.