1900s in the Negro Leagues

The Chicago Union Giants were founded by Frank Leland in 1901. They were rechristened the Leland Giants in 1905.

The Philadelphia Giants started play in 1902, founded by Sol White and H. Walter Schlichter.

The Brooklyn Royal Giants were founded by John Connor in 1905.

The Cuban X-Giants ceased operations in 1907.

In a late-season series between the Chicago Cubs and Leland Giants in 1909, Joe Green broke his leg sliding into third on a stolen base, and attempted to score on the overthrow, hopping all the way on his uninjured leg. He was thrown out, but the play was lauded in the press afterward. The Cubs swept the three-game series from the Lelands, but the Lelands were competitive in every game.

Hall of Famers who were active at some time during this decade included Sol White, Rube Foster, Frank Grant, Joe Williams, Pete Hill, Ben Taylor, and John Henry Lloyd.