In October of 1974 my father went to Poland on business. While in the airport he saw the US amateur boxing team. I don't know the team's affiliation–1974 wasn't an Olympic year–but these were top-rate boxers. He got their signatures on a postcard:
At least four of them went on to become professional champions: Michael Spoinks, Leon Spinks, Jr., ("Sugar") Ray Charles Leonard, and Aaron Pryor.