Donald Rutherford Slater was born in Pasadena, California, on August 21, 1923. He served in World War II before rheumatic fever resulted in his honorable discharge. He enrolled at the University of Southern California and received a degree in English literature. In 1951 Slater joined the Mattachine Society, and in 1952 was one of the founders of ONE Incorporated, which published the first national gay and lesbian periodical, ONE Magazine. Actively involved in the publication of the magazine, Slater became managing editor in 1958. A disagreement between Slater and business manager Dorr Legg in 1965 sparked a battle over control of ONE that led to competing ONE publications. When Legg won the right to use the name ONE later that year, Slater started his own organization, the Homosexual Information Center (HIC), and periodical, Tangents. Slater died on February 14, 1997, survived by his partner of over 50 years, Tony Reyes.

Sources:

"Don Slater, 1921-1997: A Gay Rights Pioneer Remembered by his Friends." Homosexual Information Center, 1997.

Hansen, Joseph. A Few Doors West of Hope: The Life and Times of the Dauntless Don Slater. Homosexual Information Center, 1998.