Documents from gay rights history are on display for the first time at the Library of Congress as part of an exhibit on the nation’s constitutional history and civil rights protections.

Men and women picketed the White House on May 19, 1965, to protest what they called government discrimination against homosexuals. The demonstration was organized by the Mattachine Society of Washington, which said it was acting on behalf of “the nation's second largest minority” — 15 million homosexuals. Frank Kameny is the second picketer in the line. (File photo/UPI)

Though it was denied, Kameny’s was the first petition to the high court for a violation of civil rights based on sexual orientation. He argued that the government’s actions toward gays were an “affront to human dignity.”

“This inclusion is an epic milestone in the telling of gay history because it places gay Americans’ struggle for equality where it belongs — in the story of the Constitution itself,” Charles Francis, a founder of the Kameny Papers Project, told the Associated Press.

The library quietly placed the documents on view at the end of April in an exhibit called “Creating the United States,” which traces the evolution of the nation’s founding documents and legal framework. Organizers of the Kameny Papers Project, which donated about 50,000 items to the library in 2006, planned to announce the display Monday.

The library is also displaying a 1966 letter from the head of the U.S. Civil Service Commission under President Lyndon B. Johnson, justifying the firing based on the “revulsion of other employees.” It was introduced last year as evidence in the battle over gay rights in California to show a long pattern of treatment by the federal government.

Gay rights activist Frank Kameny, being honored in 2010 with a street sign bearing his name at 17th and R streets NW. (Sarah L. Voisin/THE WASHINGTON POST)

In 1965, Kameny was the first to stage a gay rights protest, with about 10 others, in front of the White House and later the Pentagon and elsewhere; among the signs demonstrators carried was the message: “Homosexuals Ask for the Right to the Pursuit of Happiness.” He also took on the American Psychiatric Association to successfully argue that being gay or lesbian shouldn’t be defined as a mental illness.