A civil rights activist who dedicated her life to social service, Doris Jean Castle was the younger sister of the civil rights icon Oretha Castle Haley. As a teenager, Castle joined in a boycott and protests organized by the Consumers’ League of Greater New Orleans to fight the racially discriminatory employment practices of Dryades Street merchants. An early member of the New Orleans chapter of the Congress of Racial Equality (CORE), she served as the membership chair of the organization and actively engaged in picketing segregated Canal Street businesses.

Castle courageously participated in the 1961 Mississippi Freedom Rides and was arrested in Jackson, Mississippi. She and her fellow riders refused to pay bail, choosing to serve prison time as a tactic to keep the media’s attention. Castle served some of her time at the Mississippi State Penitentiary in Parchman, which was notorious for its particularly harsh conditions. The following year she participated in CORE’s "Freedom Highways," a campaign challenging segregated facilities along major highways.

During a 1963 protest of the segregated New Orleans City Hall cafeteria, police carried Castle, still in her cafeteria chair, from the building after she refused to leave. She was one of three plaintiffs who successfully sued to desegregate the facility. Working alongside her sister, Castle also helped to desegregate public transportation in New Orleans.

In the mid-1960s she left the city to raise funds for the National Welfare Rights Organization. After she returned to New Orleans in 1967, Castle worked for several social service programs, including some under the auspices of Lyndon Johnson’s War on Poverty initiative. She worked with the Urban League to challenge housing discrimination and served as a counseling specialist with Odyssey House, a behavioral healthcare facility focused on addiction treatment. Later in life she worked as an admissions supervisor at Charity Hospital.