Born in Belton, a historical populated place, in Hempstead County near Hope, Arkansas, Harris attended public schools in Prescott in Nevada County, Arkansas. In 1929, he graduated from Henderson State College in Arkadelphia, Arkansas, receiving an Artium Baccalaureus degree. Thereafter in 1930, he completed law school at Cumberland School of Law, then part of Cumberland University, in Lebanon, Tennessee, receiving a Bachelor of Laws. He was admitted to the bar in 1930 and commenced practice in El Dorado, the seat of government of Union County, Arkansas. Harris served as deputy prosecuting attorney in Union County from 1933 to 1936 and as prosecuting attorney of the 13th Judicial Circuit of Arkansas from 1937 to 1940. He served as delegate to the Democratic state conventions in 1936 and 1940, and the Democratic National Conventions in 1944, 1952, 1956, and 1960.