M. Carey Thomas was born January 2, 1857, in Baltimore, Maryland, the daughter of Dr. James Carey (1833-1897) and Mary Whitall Thomas (1836-1888), prominent Quakers and reformers. A lively child, Thomas was nurtured in the close-knit world of her deeply religious family. After graduating from the Howland School in Union Springs, New York, she attended Cornell University, where she completed the classical course in two years, graduating with a B.A. in 1877.

Returning to Baltimore, Thomas entered the graduate program of the Johns Hopkins University but withdrew after a year, discouraged because she could not attend the seminars around which the university built its instruction. In her two Baltimore years she formed intimate friendships with Mamie Gwinn (1861-1940) and Mary Garrett, daughters of powerful and wealthy men. The three joined with two friends, Julia Rogers and Bessie King, to form the Friday Night Club. In the 1880s, the five women created the Bryn Mawr School for Girls in Baltimore, and, following Rogers's withdrawal, four of them developed the campaign that endowed the Johns Hopkins medical school and guaranteed that it be a graduate medical school open to women.

In 1879, Thomas traveled with Gwinn to study philology at Leipzig University, then she transferred to the University of Z¸rich, where in 1882 she received her Ph.D. summa cum laude. Prior to their return to Baltimore, family news had informed them of the founding of Bryn Mawr College (originally Taylor College for Women), outside Philadelphia, and Thomas began her campaign to be named president. In 1884, the board of trustees instead created for her the office of dean. This gave her the opportunity to turn the tiny college into a center of scholarship through high entrance requirements, a graduate school, and the gathering of a distinguished faculty. After Mary Garrett offered the college $10,000 for each year that Thomas served as president, the trustees appointed Thomas to the position in 1895. Thomas served until her retirement in 1922.

Thomas's early years as president were difficult, for she served under a conservative all-male board of Quaker trustees. By the early twentieth century, however, Thomas became a national educational figure, and she used her growing celebrity to overcome trustee resistance to change. Aided by John D. Rockefeller's philanthropy, she was able to develop her dream of a greater Bryn Mawr. As the college grew in size, it built one of the finest examples of collegiate gothic architecture in the United States, at the same time sustaining its intellectual quality and gradually adding women professors to its largely male faculty. In her final years as president, Thomas supported new progressive programs, including the Summer School for Women Workers in Industry.

A suffrage advocate, Thomas headed the College Equal Suffrage League and spoke brilliantly about women, higher education, and creativity. With many of her era, she shared beliefs in women, science, and progress that were joined to nativism, racism, and anti-Semitism, and within the educational institutions she served, she sought to limit opportunity to white Protestants of British descent. In the years following retirement, she focused on creating facilities for women to study abroad. In the 1920s she supported the Equal Rights Amendment. Among her many tributes was an honorary doctorate from Johns Hopkins. At Bryn Mawr College's fiftieth anniversary, November 1935, she spoke in public for the last time. She died in Blue Ridge Summit, Pennsylvania, on December 2, 1935.

Dobkin, Marjorie Houspian, ed. The Making of a Feminist: Early Journals and Letters of M. Carey Thomas. Kent, Oh.: Kent State University Press, 1979.

Horowitz, Helen Lefkowitz. The Power and Passion of M. Carey Thomas. New York: Alfred A. Knopf, Inc., 1994; Urbana: University of Illinois Press, 1999, paperback.