David Thomas (March 22, 1905 ā July 27, 1968), nicknamed "Showboat", was an American first baseman in the Negro leagues from 1929 to 1946. A native of Mobile, Alabama, Thomas is considered one of the greatest defensive first basemen in Negro leagues history. In 1945 at age 40, he and Terris McDuffie were given a tryout by Branch Rickey and the Brooklyn Dodgers, two years prior to Jackie Robinson's breaking of the baseball color line. Thomas died in Mobile in 1968 at age 63.