More than anything else, money changed professional sports during the 1970s. In football and baseball, moneymaking television contracts led to changes in the rules and a lengthening of the season. Playoffs in both sports extended the seasons and brought huge revenues. Players wanted a share of the increased revenues, and players unions organized to demand higher pay and more freedom to move from team to team. In baseball, a policy called "free agency" moved players around and helped a number of players reach salaries at or near $1 million a year.

Professional baseball was dominated by the Cincinnati Reds, led by Pete Rose (1941–), and the Baltimore Orioles, led in 1970 and 1971 by Frank Robinson (1935–), who would become baseball's first black manager in 1975, with the Cleveland Indians. Strong runs by upstart teams like the Oakland A's and the Pittsburgh Pirates made it an exciting decade for baseball...