First day cover honoring the centennial of baseball, postmarked at Cooperstown on June 12, 1939, signed in fountain pen, "Ty Cobb." In fine condition. Accompanied by a full letter of authenticity from JSA. This three-cent postage stamp honoring baseball's 100th anniversary was issued in conjunction with the dedication and opening of the National Baseball Hall of Fame in Cooperstown, New York, on June 12, 1939. Ty Cobb, remembered for his quick bat and fearsome skill on the basepaths, was enshrined as a member of the Hall of Fame's first class, elected in 1936. Encapsulated in a PSA/DNA authentication holder.