Warren Giles was elected president of the Moline, Illinois, Plowboys baseball club in the Class B Three-I League at age 23 in 1919, beginning his 50-year career in baseball. He then joined the St. Louis Cardinals’ organization and rose to prominence as the president and business manager of their top-level farm teams, the Syracuse Stars (1926–27) and Rochester Red Wings (1928–36) of the International League. As a foreshadowing of his most powerful position in professional baseball, Giles spent part of the 1936 season as president of the International League. Upon the recommendation of Cardinals’ executive Branch Rickey, Powel Crosley, Jr., owner of the Cincinnati Reds, appointed Giles as his club’s general manager and president on November 1, 1936, succeeding Larry MacPhail. While the 1937 Reds won only 56 games and slid into the basement of the National League, the 1938 edition improved by 26 games to finish in the first division, earning Giles the 1938 Major League Executive of the Year award from The Sporting News. That season, on June 13, Giles swung one of the most successful trades in Cincinnati history, when he obtained starting pitcher Bucky Walters from the Philadelphia Phillies for catcher Spud Davis, pitcher Al Hollingsworth and cash. Walters would help lead the Reds of 1939 and 1940 to back-to-back National League championships. The 1939 Reds—with Walters winning 27 games and the league Most Valuable Player award—captured the NL pennant by 4½ games, but they were swept by the New York Yankees in the World Series. Unfazed, the 1940 Reds won 100 games (with Walters accounting for 22 victories and leading the NL in earned run average for a second straight season) to repeat as league champions by a 12-length margin. Then, behind Walters’ two complete game victories, the Reds defeated the Detroit Tigers in a seven-game World Series for the second world title in modern club history.

The Reds boasted .500 or above teams through 1944, but declined beginning in 1945 and during the postwar era finished in the NL’s second division and posted losing records for Giles’ last seven seasons as the Reds’ top executive. Nevertheless, Warren Giles was a leading candidate to become baseball’s third commissioner after Happy Chandler was fired in 1951. He was runner-up in the commissioner balloting to Ford Frick but succeeded Frick as president of the Senior Circuit on October 8, 1951. During his 18-year reign as chief executive of the National League (including the full seasons of 1952–69), Warren Giles presided over several historic events. The NL opened the West Coast and Southeastern United States territories by approving the transfers of the Los Angeles Dodgers and San Francisco Giants in 1958, and the Atlanta Braves in 1966. Giles’ first full season, 1952, was the last in which the eight-team league operated in the same cities as it had since 1900. In March 1953, the Braves pulled up stakes in Boston, where they had played since they were charter members of the Senior Circuit in 1876, and moved to Milwaukee. That transfer—initially wildly successful, although the Braves’ tenure there would last only 13 seasons—was the first in the series of franchise moves that shook Major League Baseball for the next two decades.

In addition, Warren Giles’ National League expanded to 12 teams by adding two clubs in both 1962 and 1969. Although “who says you have to have a team in New York [City]?” was Giles’ notorious reply when asked if his league would seek to replace the Dodgers and Giants in New York, the 1962 expansion, which created the Mets, returned the Senior Circuit to the city. The same expansion brought Major League Baseball to Texas, with the Houston Colt .45s. In 1969, Giles’ last year in office, his league expanded into Canada with the Montreal Expos, adopted divisional play, and played the first National League Championship Series, between the Braves and Mets. Between 1952 and 1969, the NL’s member clubs, with the exception of the Chicago Cubs, also opened or were planning to open new stadiums. Warren Giles’ presidency also saw the National League widen its advantage over the American League in the signing of African-American and Latin American players, resulting in a three-decade-long dominance of the Major League Baseball All-Star Game. In clubhouse meetings before the midsummer classic, Giles famously would exhort the NL’s players to uphold their league’s honor. During his tenure, the National League won 16 of 22 All-Star games played, with one tie. (Two games were played each year from 1959 to 1962.) The NL also won ten of 18 World Series during Giles’ term.

In addition, Warren Giles worked vigorously to keep premier players in his league. After the advent of interleague trading without waivers in November 1959, he lobbied against the trade of National League superstars to the American League to preserve the NL’s hegemony. He was successful until his former team, the Reds, traded Frank Robinson to the Baltimore Orioles after the 1965 season. During the early weeks of the 1963 season, Giles became a figure of some controversy after he instructed the NL’s umpires to strictly enforce the balk rule then in place. In response, the Senior Circuit’s arbiters called 74 balks from the opening of the season on April 8 until April 26, when Giles announced a relaxation of the policy. Only two balks were called in the American League over the same period. Giles, then 73, announced his intention to retire after the 1969 season and on December 5, Giants’ executive Chub Feeney was elected to succeed him. Under Feeney, league president through 1986, the NL’s All-Star Game dominance would continue, with 14 triumphs in 17 games. Warren Giles was elected to the Cincinnati Reds Hall of Fame in 1969 and the Baseball Hall of Fame by the Veterans Committee in 1979 shortly after his death in Cincinnati at age 82. Giles is interred in Riverside Cemetery in Moline, Illinois.