In the mid-1960s, when pro football eclipsed baseball as America's leading spectator sport, the NFL had the most exciting season in its history. The Eastern Conference Cleveland Browns were the champions in 1965 yet most of the action was in the Western Conference, where the reigning Baltimore Colts contended with the formidable Green Bay Packers and Chicago Bears. All three teams played two games apiece against the Detroit Lions, a power earlier...