WASHINGTON — Tributes poured in Wednesday for Frank Kameny, a pioneer of the gay rights movement in the United States who died the day before in Washington at the age of 86.

"The death of Frank Kameny is a profound loss and he will be greatly missed," the National Gay and Lesbian Task Force said in a statement that remembered him for coining the slogan "gay is good."

A native New Yorker with a Harvard doctorate, Kameny took up the struggle for gay rights in 1957 when he was fired as a government astronomer because of his sexuality -- a sacking that he took to the Supreme Court.

He went on to challenge laws that discriminated against homosexuals, and the once-widely-accepted notion that homosexuality is a mental disorder -- a notion that was finally swept aside in 1973.

In 1971 he was the first openly gay candidate for Congress, but it was not until 2009 that the US government, through its Office of Personnel Management, formally apologized for having fired him.

"It took 50 years, but I won my case," he said at the time.

More recently the World War II veteran was among the front-row dignitaries when President Barack Obama signed an end to the "don't ask, don't tell" rule that prevented gays in the military from coming out.

Some of the "gay is good" posters that he carried during protest marches outside the White House in the 1960s are now in the collection of the Museum of National History, and a street in Washington bears his name.

His personal archives, containing more than 70,000 letters, documents and memorabilia, were deposited with the Library of Congress five years ago after spending decades in his attic.

Kameny had the distinction of dying once before, in 2007 when the gay rights magazine The Advocate erroneously reported he had succumbed to AIDS. He accepted its apology with humor, saying: "Did you give a date of death?"

"Frank Kameny sparked national change and set the example for gay and lesbian Americans to live their lives openly and proudly," said Mike Thompson of the Gay and Lesbian Alliance Against Defamation, via The Advocate website.

"He taught us the power that our visibility and stories have in changing hearts and minds.... We honor Frank's legacy not only by remembering this pioneer, but by continuing his work to speak out and share our own stories."