Prout founded a day school in Baltimore in 1830, and taught there until its closure in 1867. Prout was a member of the Bethel African Methodist Episcopal Church. She was involved in other humanitarian ventures; a trusteeship of the Gregory Aged Women's Home, president of the local chapter of the National Reform Educational Association, and founded a secret order in 1867 that became the Independent Order of St. Luke, a Black aid organization.
The Independent Order of St. Luke was founded in Baltimore, Maryland, in 1867 by Mary Ann Prout. Originally a women's only aid society, it allowed men to join in the 1880s.