Louisa Parke Costin (1804–October 31, 1831) established a school for African American children in 1823. Located on Capitol Hill in Washington, D.C., it was known as the first public school for black children in the city. She was related to Martha Washington through her father John Dandridge, who was Costin's paternal grandfather. Martha Washington was her mother's slaveholder. When Washington died, her granddaughter Elizabeth Parke Custis Law inherited Delphy. Two years later, Delphy and her daughters Louisa and Ann were manumitted by Elizabeth and her husband Thomas Law.