Rube Foster

Some historians have said that Foster's tireless work in establishing and managing the NNL and his own team had ruined his health by the mid-1920s. In 1925 he was exposed to a gas leak in a room in Indianapolis and was pulled from the room unconscious. Although he recovered, his health was never the same. In 1926 his behavior became so erratic that he was placed in the Illinois State Hospital in Kankakee, where he lived out the rest of his life. Although he talked constantly of baseball and wanted desperately to win another pennant, Foster never saw his Giants play in the Negro World Series for which he had worked so hard. He died of a heart attack on December 9, 1930. More than 3,000 mourners attended his funeral in Chicago, standing in icy rain and wind to witness the procession and pay their respects. He was eulogized as the "father of Negro baseball." His widow, Sarah Watts Foster, was unfamiliar with his business arrangements and realized no benefits from his ventures. His partner, John Schorling, had sold the American Giants to a white florist, William E. Trimble, in 1928. Although black businessmen bought it in 1930, the team never reached its former level.

The NNL dissolved in 1931, during the Great Depression, after several years of declining financial success and the absence of Foster's guiding hand. It was revived, however, in the mid-1930s, and black teams went on to play in the Negro leagues until about 1960, some fifteen years after Jackie Robinson became the first African-American player of the twentieth century to sign with a white major league team. The integration of African-American players into the major leagues caused fans to follow those teams with greater interest, and the Negro leagues declined and finally folded.