In 1921, trailblazing economist Sadie Tanner Mossell Alexander (1898–1989) earned a doctorate in economics at the University of Pennsylvania, becoming the first Black American to earn a Ph.D. in economics. She also became the first Black woman member of the Pennsylvania bar and the first Black woman to serve as assistant city solicitor. She and her husband, attorney Ray Pace Alexander, founded the National Bar Association. In 1946, Sadie was selected to become a member of President Truman’s new Committee on Civil Rights, where she helped to lay the groundwork for future legislation. In 1951, she co-founded the Commission on Human Relations of the City of Philadelphia, serving as a member of the commission from 1952 to 1968. in 1979, President Jimmy Carter appointed her to be chairperson of the White House Conference on Aging.
Born in Philadelphia, Pennsylvania, two decades before women gained the right to vote, Sadie spent part of her childhood in Philadelphia and part in Washington, D.C. She came from a family of successful men. Her father, Aaron A. Mossell, was an attorney. Her maternal grandfather, Benjamin Tucker Tanner, had been the bishop of the African Methodist Episcopal Church. Her uncle Henry Ossawa Tanner was a noted painter, and another uncle, Nathan F. Mossell, was a surgeon and the founder of Mercy Hospital (later Mercy-Douglass Hospital) in Philadelphia.
At the University of Pennsylvania, before earning her Ph.D., she earned a bachelor's degree in education and a master's degrees in economics. She later graduated from the university's law school, with honors, becoming the first African-American woman to graduate from that law school.