Postmarked in Cooperstown, NY on Hall of Fame Induction Day - August 12, 1974 this 3.5" x 6.5" envelope has been signed by all living members at the time from the 1974 Induction class. The included postmark could only have been applied by the US Postal Service in Cooperstown, NY on that very day making it likely the signatures were obtained on Induction Day as well. Lack of an addressee also leads us to conclude an astute collector had the envelope hand canceled by the Cooperstown Post Office for the express purpose of marking the occasion before or after obtaining the signatures. Signatures include: 1) Cool Papa Bell 2) Jocko Conlan 3) Whitey Ford 4) Mickey Mantle. A unique collectible from a historic day for baseball and the Hall. Full LOA from PSA/DNA.