The battle for gay civil rights in the United States really began when those rights were abruptly taken away in the 1950s.

President Dwight Eisenhower presided over a sweeping purge of homosexuals in the Federal government, which opened the floodgates for discrimination across a wide range of fields, in large parts of American life.

Careers were derailed, lives were ruined and some of those thus discriminated against began the long campaign, in the courts and in the court of public opinion, to get this injustice reversed, public recognition for their cause and the media to stop participating in the name calling, scapegoating and persecution.

“The Lavender Scare” is the title of a new documentary about this “Red Scare” era assault on a vulnerable minority. It’s a film built around the letters and public pronouncements of a pioneer, a reluctant but combative, persistent and successful leader in this fight.

Dr. Franklin E. Kameny was a Harvard-educated astronomer whose dream was to work in America’s nascent space program, a dream interrupted when he was abruptly fired from the Army Map Service as a security risk in 1957. That began a life long battle to right this live-shattering wrong and turned Kameny into “The Father of the Gay Rights Movement.”

In letters to his mother (read by David Hyde Pierce), Kameny pre-echoes Dr. Martin Luther King, Jr. when he notes that “Every American citizen has the right to be considered in the light of his own personal merit.” It took guts to make this fight, to refer to himself, in public at that time, as “a homosexual American citizen” when America’s gay community was hardly a community at all — underground, closeted pretty much from coast to coast.

Josh Howard’s eye-opening film captures the context of the times and the birth of many government sanctioned gay stereotypes

In “the panic of the Cold War,” the idea was homosexuals, forced to live secretive lives, were suddenly believed to be security risks. Even as “The Kinsey Report” came out, 1950s America was largely in the dark about this minority and its practices. It was much easier to just dismiss “them” as “perverts.”

The “Red Scare” notion that, as Senator Joseph McCarthy declared, “perverts could be blackmailed into betraying national secrets,” caught hold. And when Eisenhower took office, he eagerly took action on this McCarthy whipping boy.

David Johnson, the author of “The Lavender Scare” book on this piece of gay history, notes pointedly on camera that in this country, this sort of blackmail never happened. A Senate “Perversion” inquiry run by Republicans fails to find an instance of a security breach by a gay employee of the government. That didn’t stop “a systematic campaign…to identify and fire homosexuals.”

A retired government official of the day notes how homosexuals were “easy to identify,” and how it was “just as easy to get them to go away.” The mere threat of exposure made “them quite happy to resign quietly.”

That’s how Madeline Tress, then a 24 year-old economist with the Dept. of Commerce, lost her career. Questioned by the FBI, “the most demeaning thing,” she faced insults that she was “not at all feminine, “”manish” wearing “no lipstick” — all documented in her file with J. Edgar Hoover’s F.B.I.

“My career was over before it began.”

The interrogators worked with “tables” that made “guilt by association” accusations. The accused were routinely railroaded the way Navy veteran Carl Rizzi was, outed by a “confidential informant,” confronted with photos of a drag performance he did at a local club.

If you want to know how far “Transamerica” has come, take a gander at the officials and official documents here discussing “mentally ill perverts, fond of little mustaches…sodomites…C-S-ers” (“suckers” is the second word they abbreviated) shown here.

“The Lavender Scare” lays out how official Washington’s treatment of gays was promptly aped by local law enforcement across the country, which began the litany of raids on gay bars and round ups of homosexuals wherever they cruised.

People got their names in the paper for being arrested, and some killed themselves.

Those arrested in government were strong-armed into naming “five other people you know” in true McCarthy Era blacklist fashion.

One bit of context that Josh Howard’s film points out was the vast human mobilization of World War II, when isolated gays from all over America found out they weren’t alone when they were drafted into the service or enticed to various cities for government work.

We see the camera panning over scads of snapshots of gay couples, in and out of the service, read the headlines about “deviates” as protests began in the late 50s, when even the ACLU refused to fight on their behalf.

“Pickets call Nation ‘Unfair’ to Deviates”

One important contextual sin of omission is worth noting. There was a precedent, glaringly obvious, for fearing that homosexuals working with sensitive information could be compromised. It was happening “across the pond,” gays being blackmailed into spying or continuing to spy for the Soviet Union against Britain and NATO. Much of what was known about the Cambridge Spy Ring did not become public until years later, but in espionage circles it was suspected or recognized at about the time The Lavender Scare became policy.

All the public attention and call for “action” against “commies” and “queers,” began in 1948, “the year America worried about homosexuality,” and didn’t officially end until Bill Clinton overturned the last of the edicts of that age, and pushed “Don’t ask, don’t tell” as a military enlistment policy he thought he could sell the public on.

All of which is important history to remember, with the speed of social change today such that the first openly gay politician to run for president and be taken seriously is a part of the day’s conversation.

And straight America can finally get to know the name of Dr. Frank Kameny, a very smart man with a very big grievance against the government, one he was willing to endure mockery and the loss of his original career to settle.

MPAA Rating: unrated

Cast: Narrated by Glenn Close, Joan Cassidy, Carl Rizzi, John D’Emilio, Lillian Faderman, with the voices of David Hyde Pierce, Cynthia Nixon, T.R. Knight and Zachary Quinto

Credits: Directed by Josh Howard. A Full Exposure release.

Running time: 1:14