This choice image of Three Finger Brown was taken early in his career in circa 1903-1907, note how thin he is. The stadium is consistent with Washington Park, home of the Brooklyn Superbas during that period. Brown was with the St. Louis Cardinals in 1903 and the Cubs thereafter. The uniform could match with St. Louis and is a definite match with the Cubs from 1904-1907.
There is a Paul Thompson stamp on back from Thompson’s earliest period circa 1905.
The back pocket of Brown’s pants match the back pocket of this known 1904 Conlon image of Evers.