Garcia served as legal advisor to the League of United Latin American Citizens In 1939–40. He was elected to the San Antonio Independent School District Board of Education in April 1948, but later resigned. He helped revise the LULAC Constitution to permit non-Mexican Americans to become members in 1949. In that year, he also served as lawyer to the family of Felix Longoria, and helped contract negotiations for the rights of workers in the United States-Mexico Bracero Program. On May 8, 1950, Garcia and George I. Sanchez appeared before the State Board of Education to seek desegregation enforcement. Garcia was legal advisor to the American G.I. Forum from 1951 to 1952. He helped pass an anti-discrimination bill in Texas. Garcia served on the first board of directors of the American Council of Spanish Speaking People, and the Texas Council on Human Relations, and helped the School Improvement League, the League of Loyal Americans, the Mexican Chamber of Commerce, and the Pan American Optimist Club. In 1952, the University of Texas Alba Club named him "Latin of the Year."