On June 12, 1939 the first ever Baseball Hall of Fame induction ceremony happened. This is an unbelievable relic from that ceremony. This is an envelope that is commemorating the 100th anniversary of Baseball signed boldly by Babe Ruth. Not only that but it is dated June 12, 1939 and stamped by the US Postal Service as the First Day of Issue on it. These are extremely collectible especially signed by one of those players who were invited for the ceremony.
 
This comes authenticated and graded as an 8 by PSA.