Harris' playing career began with the Atlanta Crackers of the A1 Southern Association in 1937. His catcher that season was Paul Richards, who in 1938 became Atlanta's player-manager. Richards and Harris would form a decades-long association in baseball at the minor and major league levels.
Harris compiled a 35-63 record with a 4.16 earned-run average in 151 American League games with the Philadelphia Athletics and (briefly) Washington Senators from 1941-47. The remainder of his major league career would be spent working in tandem with Richards, initially as a coach with the Chicago White Sox (1951-54), Baltimore Orioles (1955-61), and Houston Colt .45s (1962-64). In each case he worked under Richards, who was either his manager, general manager, or (in Baltimore from 1955-58) both.
In 1965, Harris was promoted by Richards to manager of the newly rechristened Houston Astros, serving for the team's debut season in the Astrodome. It was actually his second major league managerial post: he had briefly managed Baltimore in September 1961 when Richards resigned to take the front office reins of the expansion franchise in Houston.
After Richards became vice president for baseball operations (in effect, general manager) of the Atlanta Braves of the National League during 1966, Harris followed as manager of AAA Richmond, and, then, from 1968 to the middle of the 1972 season, as manager of the big-league Braves. Harris led Atlanta to the first-ever National League West Division championship in 1969, but his Braves lost the National League Championship Series to the eventual world champion New York Mets in three straight games.
When the Braves slumped, Richards was fired during the 1972 season, and Harris was replaced as manager by former Braves third baseman Eddie Mathews. Harris' final major league managerial record was 466-488.
- Lum Harris. (2007, October 13). In Wikipedia, The Free Encyclopedia. Retrieved 16:56, January 15, 2008 
- Baseball-Reference.com - career managing record and playing statistics