Pan-American games, amateur athletic competition among representatives of countries in the Western Hemisphere. The competition, held every four years, follows the organization and eligibility rules of the Olympic games and is held in the year before the Olympics in different host cities. World War II delayed the first Pan-American games, originally planned for 1942, but not held until 1951. There were 19 events in the 1951 games, but a full schedule of Olympic sports now comprises the program. The United States has usually dominated the events.