Series I. Abraham Lincoln Brigade Archives Administrative Files (1937-2024) includes files related to the Abraham Lincoln Brigade Archives (ALBA) and the Veterans of the Abraham Lincoln Brigade (VALB) as organizations. This series contains administrative files such as documents of the Board of Governors, applications for funding, budget documents, administrative correspondence, and files of the ALBA Bay Area chapter. This series also contains issues of ALBA's journal, The Volunteer (formerly known as The Volunteer for Liberty), as well as submissions, drafts, and correspondence with readers; documentation of VALB projects and campaigns such as the Nicaraguan Ambulance Project and the Nicaraguan Wheelchair Repair Project, during which veterans fundraised to provide aid to those affected by the Nicaraguan Revolution; and teaching materials on the Spanish Civil War, including the professional development workshop "America and World Fascism: From the Spanish Civil War to Nuremberg and Beyond," which was taught online and across the Northeast United States.

Event files in this series contain planning documentation, such as correspondence, meeting minutes, travel itineraries, and event contracts; ephemera, such as flyers, pamphlets, playbills, and postcards; photographs; and recordings of ALBA and VALB events. Events in this series include anniversary dinners and gatherings from 1976-2002; Spanish Civil War anniversary commemoration gatherings and ceremonies; monument dedication ceremonies; memorial services; film screenings; and exhibitions, such as "Barcelona: The Forgotten Olympics of 1936" (1992), "Shouts from the Wall" (1994-2002), "The Aura of the Cause" (1997), "Drawings of the Spanish Civil War: Luis Quintanilla" (1999), "They Still Draw Pictures: Children's Art in Wartime" (2000), "Facing Fascism: New York and the Spanish Civil War" (2005), "Ralph Falsanella: Artist of the People" (2006), and "Art and Politics: Posters from the Spanish Civil War, 1936-1939" (2007).

Series II. Spanish Civil War Research Files (1930-2022) contains research material gathered and created by Peter Carroll on the Spanish Civil War and the Abraham Lincoln Brigade.

Series III. Oral History Interviews (1977-1999) includes audio recordings and transcripts of Spanish Civil War veteran interviews, as well as administrative files and press clippings for the Radical Elders Oral History Project. Interviews with Eluard Luchelle McDaniels and Vaughn Love were conducted by Peter Carroll for the Radical Elders Oral History Project. Other interviews in the series are not labeled with a specific project, and some were likely conducted by Carroll for research during the writing of The Odyssey of the Abraham Lincoln Brigade: Americans in the Spanish Civil War.