Mr. Francis, working with pro bono lawyers at one of the nation’s largest law firms, McDermott, Will & Emery, has used public-records requests to collect hundreds of documents in which gays or policies toward them were discussed. The government has identified thousands more, and Mr. Francis says he plans to someday make the records public as part of what he calls “archive activism.”

“Gay and lesbian history is often ignored or deleted,” he said. “It didn’t happen.”

For instance, while much has been written about the F.B.I.’s first and most influential director, J. Edgar Hoover, and his hunt for communists and his suspicion of the civil rights movement, little attention has been paid to his effort to unmask gays in government and academia.

“There were two obsessions at the F.B.I. One was communism. The other was gays,” said Douglas M. Charles, a Pennsylvania State University professor who is writing a book on the F.B.I. and gays and who independently reviewed some of the same documents that Mr. Francis examined.

Under Mr. Hoover’s Sex Deviate program, the F.B.I. collected information on people suspected of being gay and passed it on to government agencies and, sometimes, the news media. The F.B.I. had a network of informants, including doctors, helping alert the authorities to what was seen as a growing national security threat, Dr. Charles said.

“The Seat of Government has been receiving an increasing number of reports, arrest records, and allegations concerning present and past employees of the United States Government, who assertedly are sex deviates,” a 1951 F.B.I. memo states.

Dr. Charles said the F.B.I. incinerated 330,000 pages of documents related to the program in 1977, leaving behind only a few scattered records. So efforts by people like Mr. Francis to make public the remaining documents, along with documents from elsewhere in government, are invaluable to historians and researchers, he said.