A. Caswell Ellis, teacher and reformer, son of Orren Littleberry and Mary Louisa (McKnight) Ellis, was born on May 4, 1871, in Franklin County, North Carolina. He received his B.A. degree in classics at the University of North Carolina in 1894, attended Harvard in the summer of that year, and received his Ph.D. at Clark University in Worcester, Massachusetts, in 1897. He did advanced study at the University of Berlin in 1905.
Ellis joined the University of Texas faculty in 1897 as adjunct professor of pedagogy. From 1908 to 1926 he served as professor of educational philosophy, and he also directed the university's extension services in 1911–13 and 1914–16. In July 1917 he incurred the wrath of Governor James E. Ferguson, who directed the board of regents to fire him because he disapproved of Ellis's extension work. Ellis's dismissal was short-lived, however, as continuing differences with the university and other problems resulted in Ferguson's impeachment and resignation. Governor William P. Hobby reinstated Ellis in the fall of 1917.
Ellis was a Democrat and a leading spokesman for prohibition and woman suffrage across the state. He worked closely with Texas suffrage leader Minnie Fisher Cunningham, and in 1918, when Texas women were allowed to vote in primaries for the first time, he assisted Cunningham and the Texas Equal Suffrage Association with financial and political planning in their successful endeavor to elect Annie Webb Blanton as state superintendent of public instruction. Ellis also worked in the 1919 campaign for a constitutional amendment to give Texas women full voting rights, by serving as editor of the Texas Democrat, a suffrage newspaper circulated during the effort.
In 1926 he moved to Ohio to become director of Cleveland College, a downtown adult-education facility of Case Western Reserve University. The college was started by former University of Texas president Robert E. Vinson, who was serving as Western Reserve president when Ellis was hired to run the adult school. Under Ellis's leadership Cleveland College grew from 1,400 students to approximately 7,000. In 1941 he resigned his position, was named director emeritus of the college, and returned to Texas.
In Austin he remained active as a lecturer and consultant. He was appointed adult-education counselor for the University of Texas in 1942, and in 1946 became director of the University Evening College. He also was active in the Texas Society for Mental Hygiene, and in 1946 served as president of the Austin-Travis County Mental Hygiene Society. Ellis was a fellow of the American Association for the Advancement of Science; president of the Association of Deans and Directors of University Evening Colleges in 1940–41; and a member of the Southern Educational Association, the Society for the Scientific Study of Education, the National Education Association, Kappa Alpha, and Phi Beta Kappa. He was author of a number of articles on education and was joint author with E. J. Kyle of Fundamentals of Farming and Farm Life (1912). He served as president of the Texas Pecan Association in 1947. He married Mary Heard (see ELLIS, MARY HEARD) in July 1901. He died in Austin on October 9, 1948, after suffering from heart disease, and was cremated. His wife established a mental health collection at the Austin Public Library in his memory.