In the era of segregated baseball, the 1909 and 1910 leagues were integrated, with the Leland Giants joining as a member.

This occurred a year after major league stars Ty Cobb and Tommy Leach had approached Callahan about the possibility of leaving their teams to join the Logan Squares.

The major leagues formally recognized player contracts with the Chicago clubs.

[12][13][7][8][14] It was reported that the Leland Giants won the 1909 Chicago City League championship by 7.0 games with a 31-9 record.

[19] On August 27, 1910, the Logan Squares and Rogers Park played a night game, using a temporary lighting system.

Callahan played center field for his team in 1910 and led the league in stolen bases with 38, while hitting .333.

[17][8] [20] The Chicago City League's yearly standings and team records are unknown.

It was reported the Leland Giants won the league championship in 1909 and 1910, with the 1909 team winning by 7.0 games, with a 31-9 record.

Reportedly, the 1910 Leland Giants played home games at a Auburn Park, located where Wentworth Gardens is today.