Carlos Eduardo Castañeda, historian and professor, was born on November 11, 1896, in Ciudad Camargo, Tamaulipas, Mexico, the seventh child of Timoteo and Elisa (Leroux) Castañeda. He moved to the United States in 1906 and graduated as valedictorian from Brownsville High School in 1916; a year later he moved to Austin and embarked on a long and distinguished academic career. He received his A.B. in 1921 (with induction in Phi Beta Kappa), his M.A. in 1923, and Ph.D. in 1932, all from the University of Texas. During this period he worked as a teacher of Spanish in high schools in Beaumont and San Antonio and from 1923 to 1927 as associate professor at the College of William and Mary in Virginia. In 1927 Castañeda became librarian of the Genaro García Collection (see NETTIE LEE BENSON LATIN AMERICAN COLLECTION) at the University of Texas. While retaining his position as librarian, he also served as associate professor of history from 1939 to 1946. During World War II Castañeda took a leave of absence to serve as regional director of the President's Committee on Fair Employment Practice. In 1946 he became professor of Latin-American history, a position he held until his death.
Castañeda's scholarly interests centered in the history of the Catholic Church in the Spanish Borderlands. His principal work was the seven-volume Our Catholic Heritage in Texas, 1519–1936, with Supplement that brought the story to 1950. He translated Juan Agustín Morfi's History of Texas, 1673–1779 (1935) and (with Jack A. Dabbs) compiled the Guide to the Latin American Manuscripts in the University of Texas Library (1939). He also published numerous scholarly articles on history.
Castañeda was awarded many honors, among them the presidency of the American Catholic Historical Association (1939), knighthood in the Equestrian Order of the Holy Sepulchre of Jerusalem (1941), and Knight Commander of the Order of Isabel the Catholic from the Spanish Government (1950). He also received honorary doctorates from St. Edward's University in Austin (1941) and the Catholic University of America in Washington (1951), as well as the Junípero Serra Award of the Americas from the Academy of American Franciscan History in Washington (1951). On December 27, 1921, at San Fernando de Bexar Cathedral in San Antonio, Castañeda married Elisa Ríos; they had three daughters. Castañeda died on April 3, 1958, and was buried at Mount Calvary Cemetery in Austin. The Perry-Castañeda Library at the University of Texas at Austin, which opened in 1977, was named for him and Ervin S. Perry.