Mary Marshall Clark has been involved in oral history since 1991 and has directed projects on the Carnegie Corporation, the Atlantic Philanthropies, the Council of Foreign Relations, the Japanese Internment on the East Coast, the Apollo Theater, and Women in the Visual Arts. She was also the co-principal investigator of the September 11, 2001 Oral History Narrative and Memory Project which documented the experience of eye-witnesses and immigrants in over 1,000 hours of interviews. Mary Marshall worked at the New York Times as an oral historian and filmmaker. She served as the president of the Oral History Association from 2001-2002 and has served on the International Oral History Association Executive Council.

Mary Marshall Clark is the Director of the Columbia Center for Oral History Research and co-founder and co-director of the Oral History Master of Arts Program at Columbia University. Her current work focuses on Guantanamo Bay and the global impact of torture.