Born in Tiskilwa, Illinois, Giles attended Washington and Lee University and served as an infantry officer in France during World War I.

[1] Before becoming a full-time baseball executive, he worked as a football and basketball official in the Missouri Valley Conference, a major U.S. college sports league.

[3] He eventually 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 (1926–1927) and Rochester Red Wings (1928–1936) 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 on November 1, 1936, succeeding Larry MacPhail.

The 1939 Reds, behind Walters' 27 victories and MVP-Award-winning season, captured the NL pennant by 4+1⁄2 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 circuit in earned run average for a second straight season.

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.

That transfer — initially wildly successful, although the Braves would stay in Milwaukee only 13 seasons before settling in Atlanta — was the first in the series of franchise moves that shook Major League Baseball for the next two decades.

[5] 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.

[6] 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 as president of the National League.