New York University's Tamiment Library established the Oral History of the American Left (OHAL) in 1976. The purpose of this project was to expand the archive's documentation of radicalism and labor by recording the memories of veteran activists before they were lost. The founders of OHAL were working within the milieu of "new social history" and were intent on using the Oral History of the American Left to collect stories from groups often underrepresented in traditional historical narratives including rank and file activists, women, and ethnic minorities. The project founders, by their own admission, were a part of a revival of interest in folkloric community histories and captivated by the ability of the recorded interview to bring these stories to life. They also were cognizant of the interviewer’s role in shaping an oral history, and the interviewers' own activism is also frequently on display. As such, decades later, the early interviews of the collection not only give insight into the experiences of activists from the 1910s-1960s, but illuminate the psychology of the Left during the Reagan era.
Paul Buhle was the director of the project from its founding, and was its most prolific interviewer. Other staff included Roger Keeran who was co-director in the early years and Jon Bloom who joined the project in 1977 to work as an interviewer, coordinator, and fundraiser. Additional OHAL staff in the 1980s included interviewer and project coordinator Ruth F. Prago, interviewer Bea Lemisch, and indexer Ameila Green.
Interviewing began with a series of small grants provided by the Rabinowitz and Bronson Cutting Foundations. The New Jersey Historical Commission provided funding in 1978 to support interviews on radicalism in New Jersey between 1930 and 1960. Later, Ruth F. Prago developed the idea to start a radio series based on interviews held for the OHAL collection. Together with Pacifica Radio the project received a one-year grant from the New York State Council for the Humanities to conduct interviews with twenty-five women about radicalism during the 1930s. Radio producers used these interviews to create the radio series "Grandma was an Activist," first broadcast in 1983. OHAL received major funding in 1982–1983 from the National Endowment for the Humanities. This support enabled Paul Buhle to build a comprehensive collection of oral histories regarding ethnic-immigrant radicalism, its press, and fraternal organizations. The NEH grant also enabled OHAL to collect hundreds of hours of interviews made by filmmakers on American anarchism, the Hollywood blacklist, the Communist Party, the Columbia University student strike of 1968, and other subjects.
From its founding, OHAL was intended to be a comprehensive document of the experiences of the members of the Left in the United States, and it was assumed that the collection would continue to grow over time. Tamiment Library continued to conduct interviews and collect interviews from third parties through the 1990s and into the early 2010s.