St. Andrew's was founded in 1929 by A. Felix du Pont (1879–1948), a member of the Du Pont family, which made its fortune in the chemical industry. It was founded to provide a top education to boys of all socio-economic backgrounds, regardless of the families' ability to pay. St. Andrew's originally was an all-boys school, but became coeducational in 1973. The school also has a student-run SDLC,or Student Leadership Diversity Conference, which addresses issues of racial and ethnic diversity, and a Gender and Sexuality Alliance, which has provided social support to gay students and their allies since the early 2000s.