A flag is held over a stack of sixty boxes containing copies of an appeal filed with the Supreme Court in Washington on Monday. (Cliff Owen/AP)

The preferred terms were “pervert” or “deviate,” and if they needed further elaboration, favored adjectives included criminal, notorious, dishonest, immoral and disgraceful. There were no niceties of language when it came to the way the U.S. government treated gay and lesbian people for most of the past century.

As the Supreme Court hears arguments Tuesday about the constitutionality of gay marriage, one friend-of-the-court brief under consideration is based on a deep document dive into the government’s decades-long war on gay and lesbian civil service employees. The Mattachine Society of Washington, D.C., with the help of its pro bono legal partner, the law firm of McDermott Will & Emery, has created an insider’s look at how the fear and hatred of gay people was codified, disseminated, defended and adapted after homosexuals were officially banned from the civil service by President Dwight D. Eisenhower in 1953.

“It took us three years of FOIAs and digging in the boxes of the National Archives,” says Charles Francis, president of the Mattachine Society, a new group researching gay and lesbian history that bears the same name as a pioneering gay rights organization. Francis used Freedom of Information Act (FOIA) requests to locate documents that show what was then known as the Civil Service Commission working diligently to fire gay and lesbian employees.

The breakthrough came in January when researchers were given a box with the labels “Homosexual” and “Suitability.” It contained CSC files rife with the kind of language that even most conservative opponents of gay rights now avoid.

“Our tendency to ‘lean over backwards’ to rule against a homosexual is simply a manifestation of the revulsion which homosexuality inspires in the normal person,” a CSC supervisor wrote in a 1964 memo typical of the era. “What it boils down to is that most men look upon homosexuality as something uniquely nasty, not just as a form of immorality.”

“It is against this historical backdrop that this culture of animus developed and permeated every institution in American life,” says Lisa A. Linsky, a partner at McDermott Will & Emery who co-led the team that drafted what has been dubbed “the animus amicus.” “This is the basis, the context, the foundation of the marriage bans that are before the Supreme Court.”

While it isn’t surprising that homophobia was acceptable in government circles in the 1950s and ’60s, the Mattachine Society research yields texture and nuance, including the specific language used to confront people accused of being gay (“The commission has received information that you have recently and in the past engaged in homosexual acts,” was the preferred opener). As efforts to fire gay employees came under increasing legal scrutiny, the documents show the CSC going to tortuous lengths to maintain its policies, changing its language and articulating new rationales.

Linsky traces the evolution of anti-gay animus in the federal government from an initial period in the 1940s when “loyalty” was the main concern, through other justifications, including “suitability” for employment and risks to national security (during the McCarthy era), to a kind of catch-all argument about the “promotion of efficiency of service,” which was essentially about the discomfort gay employees might cause in the workplace.

But as the courts and eventually the media became more sympathetic to gay rights concerns, it began to look strange that the federal government was investigating messengers, mail carriers, typists and low-level clerks under suspicion of homosexuality. Yet the policy had a strange, almost self-perpetuating life of its own, and it became increasingly costly. One fascinating document details the price tag of “suitability” investigations from 1953 to 1970. Tens of thousands of employees were pursued under the specifics of Eisenhower’s notorious Executive Order 10450, which required the federal government to terminate anyone it considered a “sexual pervert.” And the cost of these investigations increased year by year, as investigators traveled the country to dig deeper into employees’ private lives.

That diligence led to sometimes absurd consequences. In 1958, a young African American air traffic controller named William Dew was deemed “unsuitable” because he acknowledged having sex with men several times when he was a college student. Dew was heterosexual, married with three children, and openly admitted his earlier same-sex encounters, meaning he wasn’t subject to coercion. And he had a good employment record.

Dew fought his termination, and in 1964, he persuaded the Supreme Court to hear his case — at which point the Civil Service Commission reinstated him with back wages rather than risk losing a court case that might establish stricter protections for gay employees. Yet homophobia continued as policy into the 1970s and ’80s, even as social attitudes to private consensual sexual activity changed rapidly.

“You can see that they are trying to look more progressive in public than they are in their office,” says Francis.

Francis says his research into the CSC is “only the tip of the iceberg.” He is also interested in other arms of the government that played a role in perpetuating anti-gay attitudes, including the Department of Justice and the U.S. Postal Service, which “enforced anti-gay and lesbian persecution by reading people’s mail and declaring publications unmailable and obscene.”

But government officials have asserted an array of reasons for not providing documents, including privacy concerns. “The postal inspectors were ground zero for a lot of this, and we have yet to see what they have,” Francis says. “They claim [in response] to our FOIAs that they have nothing.”

The fear of losing history is twofold. There is the concern that documents will be lost or destroyed. “There were hundreds of thousands of documents destroyed after J. Edgar Hoover’s death,” Linsky says of the longtime FBI director. Francis also worries about document retention policies. “Our main concern is document destruction,” he says.

The stigma of being fired by the federal government for being gay was so strong that many people who might bear witness to it simply disappeared into whatever anonymity they could salvage. “The consequences were horrendous: Leave town, change careers, start over and hope to God no one ever found that file,” says Francis. So in many cases, these files are the only access to a dark period in gay and lesbian history.

But the loss of history also has a political dimension, as evidenced by recent debates about “religious freedom” laws championed by groups that want to create a religious exemption to laws establishing equal treatment for LGBT citizens. After a storm of controversy in Indiana, where the governor invited anti-gay activists to attend the official signing of a religious freedom law, political observers noted a strange shift in the language of politicians who had long records of championing anti-gay laws.

Indiana Gov. Mike Pence (R), who in 2010 argued against allowing openly gay and lesbian service members in the military, sounded offended when he and his state were accused of anti-gay animus: “No one should be harassed or mistreated because of who they are, who they love or what they believe,” said Pence, after declaring himself personally averse to anti-gay discrimination. It was a striking change in public rhetoric — from a politician who has otherwise consistently opposed anti-discrimination laws, HIV policies and same-sex marriage laws supported by gay and lesbian groups.

For Francis, however, one of the most disturbing signs of a new amnesia about anti-gay attitudes comes from Chief Justice John G. Roberts Jr., who argued that to claim laws against gay marriage are related to the longer history of anti-gay animus would “tar the political branches with the brush of bigotry.” In his dissent to the decision that overturned a key provision in the 1996 Defense of Marriage Act, Roberts chastised gay-marriage supporters for citing “snippets of legislative history” in making their case.

“It minimizes the history of six decades,” says Francis. “There is a unique historical experience here to gay and lesbian Americans. To minimize it by calling it ‘snippets’ is to walk away from any claims for justice.”

The process of historical recovery won’t be easy, or painless. Having participated in the government’s anti-gay agenda decades ago may be embarrassing to older politicians and retired bureaucrats. The Washington Post reported in 2009 that television commentator Bill Moyers approached the FBI looking for dirt on suspected homosexuals while he was serving in the Lyndon B. Johnson administration. Moyers didn’t respond to an e-mail request for comment, but he said at the time that he couldn’t remember the details of the incident.

But one of Moyers’s colleagues, John Macy, the longtime head of the CSC, was passionately engaged with rooting out gay people from public service. In the CSC documents, he emerges as a dogged defender of anti-gay prejudice. In a 1966 letter written to gay rights advocates, the CSC defended its policy based on a laundry list of homophobic fears: “the apprehension caused other employees of homosexual advances, solicitations or assaults, the unavoidable subjection of the sexual deviate to erotic stimulation through on-the-job use of common toilet, shower and living facilities, the offense to members of the public who are required to deal with a known or admitted sexual deviate to transact Government business . . .”

Macy reviewed the memo and deemed it “effectively done” and said it “sets out a humane, public interest position.” Macy, who went on to become president of the Corporation for Public Broadcasting, died in 1986.

The gulf between the public face of the CSC and its internal homophobia even extends to memories of Macy. Moyers, in an email, said he was "bewildered" by the claims of Macy's dislike of gay people:  "In my dealings with him he was always emphasizing the need to recruit the best person for the available position. He seemed to look on the civil service as a calling.  Of course it was a wholly different era and if he were then privately scornful of homosexuality, he was participating in an almost universal cover-up.  The fact that he never disclosed to some of us with whom he closely worked such bias -- if it existed, and from my dealings with him I have no notion whatsoever that it did -- witnesses to what we can now acknowledge was a time of vast denial."

But the researchers and authors behind the “animus amicus” aren’t out to embarrass anyone. Rather, they seek to connect the past to the present, in hopes that the Supreme Court will recognize that laws against gay marriage are based on and help perpetuate bigotry.

“Who would have thought that these documents would have become relevant in the 2000s on an issue like marriage equality?” says Linsky. Without them, she says, “We wouldn’t have the evidence to back up what we as gay people know, that we were despised.”