In September 1962, Sonny Liston fought Floyd Patterson for the heavyweight title before a crowd of 19,000 in Chicago.This confrontation was preceded two days earlier by another marquee event, less kinetic but no less momentous. "The debate of the year" at Chicago's grand Medinah Temple drew a crowd of 3,000. Playboy magazine published the full transcript of the event and sold 1.5 million copies, a publication record. The debaters were Norman Mailer and William F. Buckley, Jr., rising stars of the left and right.
Source: Washington Free Beacon