Here's a card from Jack Dempsey's Restaurant in New York City with his autograph. It's postcard size card which measures 5 1/2" by 3 1/2". It has the photo on one side which is autographed, and the other side has the restaurant's name, address, and a quote from Dempsey.
Jack Dempsey opened the restaurant in 1935 on 50th and 8th Ave opposite the old Madison Square Garden. Dempsey moved the restaurant to Broadway in 1947, which finally closed in 1974. This card is from the first location so it dates between 1935 and 1947. The card refers to the "new restaurant" so this card has to be one of the earliest ones.
It was a very popular restaurant and Dempsey was very much in evidence. As it says on the card "May I play host and say hello to you in my new restaurant where food and friendliness are knockouts". Apparently their cheesecake was highly popular and people had it sent to them around the world.
A great card for a boxing fan of a great legend.