This series comprises correspondence to, by, and concerning Harry Hay from 1935 to 2002. It includes personal correspondence, correspondence related to Harry Hay and his employment, and legal correspondence regarding Harry Hay's role as executor of his father's (Henry Hay Sr.) estate between 1938 and 1942.

In addition to correspondence between individuals, the series includes letters to periodicals, open letters on organizational letter-head, and grouped correspondence focused on particular subjects. Correspondence between Hay and Jim Kepner, the bulk from the early 1960s, is notably extensive. The grouped correspondence folders include: (1) critical responses by Hay and gay scholar/activist Will Roscoe to an article authored by historian Ramon Gutierrez and published in Outlook magazine regarding Native American sexuality and gender roles, specifically the tradition of cross-gender males known as "Berdache"; (2) responses, including reviews, by Hay, Roscoe, and others to anthropologist Walter Williams' book The Spirit and the Flesh, also concerning the Berdache; (3) a contractual dispute centered on interviews with Harry Hay conducted under the auspices of UCLA's Oral history project that the interviewer, Mitch Tuchman, later sought to use as the basis of a book on Hay; (4) and letters by Hay to Don Amador and Morris Kight regarding Amador's candidacy for a state assembly seat in 1977.

For additional material on the Tuchman dispute, see the two folders labelled "RFC" (book manuscript) in the Personal series (3.1).