The first known documentary about Homosexuality has been found. It was televised on Sept. 11, 1961. You can find the documentary here:
Introduced by KQED's General Manager James Day, The Rejected was the first ever U.S. televised documentary about homosexuality, broadcast on September 11th 1961. Originally titled 'The Gay Ones', The Rejected had a budget of $100 and was filmed mostly in the KQED studio. Several sources - including co-producer Irving Saraf - refer to at least one scene being shot on location at the Black Cat Bar in San Francisco (710 Montgomery Street). However, this edit of the film does not appear to feature images of the bar. In his 'Chronological History of KQED: 40th Anniversary Edition', Jay Yamada quotes a 'Focus' article from Oct. 1979: "Jim Day reported to the board that KQED had completed videotape production of a 90 minute documentary on homosexuality in San Francisco, a program entitled 'The Rejected'." The video edit preserved by the Library of Congress is only 60 minutes long.