He was admitted to the Texas Bar in 1938, and worked as an assistant for the district attorney of Bexar County, Texas John Schook in 1938, and city attorney Victor Keller in 1941. In 1941 he was drafted into the United States Army. He became a first lieutenant in the United States Army, and was stationed in Japan with the judge advocate corps. Garcia participated in the founding of the UN in San Francisco in 1945. On February 1, 1947, he joined the office of the Mexican Consulate General in San Antonio, Texas. In April 1947, Garcia filed suit against Cuero, Texas school authorities to force closure of the segregated schools for Mexicans there. After the Mendez v. Westminster ISD case ended de jure segregation of Mexican-descent children in California, Garcia filed a similar suit in Texas, aided by R. C. Eckhardt of Austin and A. L. Wirin of the American Civil Liberties Union of Southern California. Delgado v. Bastrop ISD (1948) made the segregation of children of Mexican descent in Texas illegal.