 Among the noteworthy manuscript collections are more than 200 boxes of material donated by early lesbian activists Del Martin and Phyllis Lyon.Lyon and Martin were cofounders of the Daughters of Bilitis, the first lesbian organization in the United States, and their papers at the society include the complete surviving office records of the organization.The society's holdings also include a substantial group of administrative records from the Mattachine Society, the first enduring homosexual rights organization in the United States.