The National Park Service transferred the Frederick Douglass Papers to the Library of Congress between 1972 and 1974 to ensure their proper custodial care and to make them more readily accessible to researchers. In 1975 additional Douglass materials were acquired by the Library of Congress and added to the Frederick Douglass Papers as the Addition I Series. The papers were microfilmed and made available to the public. The online Frederick Douglass Papers at the Library of Congress has been digitally scanned from a thirty-four-reel microfilm set. Since the microfilming was performed, additional materials have been received; they are currently contained in the Addition II Series. These new materials have not been microfilmed and are not included yet in this online collection.