Sadie Tanner Mossell Alexander was a pioneering Black professional and civil rights activist of the early-to-mid-20th century. In 1921, Mossell Alexander was the second African-American woman to receive a Ph.D. and the first one to receive one in economics in the United States. In 1927, she was first Black woman to receive a law degree from the University of Pennsylvania Law School and went on to become the first Black woman to practice law in the state. She was also the first national president of Delta Sigma Theta sorority, serving from 1919 to 1923.

Aaron Albert Mossell II was the first African-American to graduate from the University of Pennsylvania Law School.