Pre-1870 John C. Heenan CDV by Fredricks. This is the earliest verifiable boxing card.
1904 Jeffries-Munroe cabinet card by Sporting Life magazine. Printed rather than photographic, and double-sided. Only one specimen is known.
Benny Leonard standup card from the Flying Fists serial.
Adam Hats Jake LaMotta premium. Only one I've ever seen.
An Israeli "Cassius Clay issue from the late 1960s. Blank backed and on thin paper.
1938 NX5 American Sweets Joe Louis
1919 Dempsey-Willard PC
My favorite PC of the Rock, ever.
A very tough die-cut Joe Louis restaurant PC from the 1950s
A mail response card sent by the studio to fans who wrote in about Jack Dempsey's serial "Daredevil Jack."
A ticket from one of the light rail systems in Los Angeles, from December 1936, depicting Joe Louis
A ticket and rain check from a bout night at Jim Jeffries' Barn