Alexander, Sadie Tanner Mossell (03 January 1898–01 November 1989), economist and lawyer, was born in Philadelphia, Pennsylvania, the daughter of Aaron Mossell, an attorney and the first black graduate of the University of Pennsylvania Law School, and Mary Tanner. While a young girl her father abandoned the family, and she was raised by her mother with the assistance of relatives.
Alexander received her degrees from the University of Pennsylvania With her Ph D in economics awarded in 1921 she became the first African American woman to receive a doctorate in economics and among the first three African American women to receive a doctorate in any field in the United States Her doctoral dissertation The Standard of Living among One Hundred Negro Migrant Families in Philadelphia was a thorough social survey investigating spending patterns from 1916 to 1918 of African American migrant families newly arrived from the South ...