1939 Baseball Centennial first day cover postmarked in Cooperstown, NY and signed by 25 members of the 1939 Boston Red Sox. Signed in steel tip fountain pen, the key signatures include that of Hall of Famer Ted Williams in his rookie season. Other signatures include Red Sox owner Tom Yawkey, Emerson Dickman, Eddie Collins (HOF - General Manager), Joe Cronin (HOF), Lefty Grove (HOF), Bobby Doerr (HOF), Tom Daly (coach), Herb Pennock (coach), Woody Rich, Joe Vosmik, Leo "Red" Nonnenkamp, Denny Galehouse, Jack Wilson, Boze Berger, Roger "Doc" Cramer, Charlie Wagner, Bill "Lefty" LeFebvre, Jim Tabor, Joe Heving, Lou Finney, Johnny Peacock, Moe Berg and Tom Carey, along with one we just can't make out (above Lefty Grove on the front of the envelope). VG/EX condition, well-preserved, though the reverse does have age-related staining from the glue inside the envelope. Full LOA from James Spence Authentication.