Alonso S. Perales, civil rights lawyer and diplomat, was born on October 17, 1898, to Susana (Sandoval) and Nicolas Perales in Alice, Texas. He was orphaned at age six and worked while still a child. He married Marta Pérez, a bookstore owner; they adopted a daughter and two sons. Perales finished public school in Alice and graduated from Draughn's Business College in Corpus Christi. He was drafted into the United States Army during World War I and received an honorable discharge. He took the civil service examination and moved to Washington; it may have been at this time that he worked a year and a half in the Department of Commerce. He graduated from the Prepatory School in Washington, studied a year in the Department of Arts and Science at George Washington University, then received a B.A. in the School of Economics and Government at the National University. In 1926 he received his law degree. In the 1920s and 1930s he went on thirteen diplomatic missions to the Dominican Republic, Cuba, Nicaragua, Mexico, Chile, and the West Indies. In 1945 he served as legal counsel to the Nicaraguan delegation at the United Nations conference. He also served under the Dwight D. Eisenhower administration.
Perales was major political leader from the 1920s until his death and was one of the most influential Mexican Americans of his time. Perales saw himself as a defender of la raza, especially battling charges that Mexicans were an inferior people and a social problem. In 1923 he wrote to the Washington Post to complain about the film Bad Man, which portrayed Mexicans as bandits. He was one of the founders of LULAC (the League of United Latin American Citizens) in 1929 and helped write the LULAC constitution, along with José Tomás Canales and Eduardo Idar. He served as the organization's third president and formed Council 16 in San Antonio, a rival to Council 2 and Manuel C. Gonzales.
In 1930 Perales testified before a United States Congressional hearing on Mexican immigration. A Democrat, he helped found the Independent Voters Association, a Mexican-American political club in San Antonio in the early 1930s. He collaborated with F. Maury Maverick and the small but emerging White liberal sector. In the 1940s he worked to introduce a bill in the Texas legislature prohibiting discrimination based on race. Perales was an intellectual who firmly believed in the law. He wrote about civil rights and racial discrimination, which he argued "had the approval of a majority." Among his books is the two-volume En Defensa de Mi Raza, which includes his essays, letters, and speeches along with other intellectuals' essays on racial discrimination in Texas. Perales was also a member of the American Legion and the San Antonio Chamber of Commerce and a columnist for La Prensa and other Spanish-language newspapers. He was an articulate public speaker, and his written and spoken Spanish was impeccable. He was greatly admired by the Mexican immigrant community. Perales died on May 9, 1960. In 1977 the Alonso S. Perales Elementary School in the Edgewood ISD was dedicated on the west side of San Antonio, and in 1990 the national LULAC convention in Albuquerque paid tribute to him.