Five years after her debut, Paving the Way, an admiring portrait of her mother Geraldine Ferraro, documentarian Donna Zaccaro returns with a brief but informative look at a crucial chapter in the fight for marriage equality in America. Her To a More Perfect Union focuses on the case Edie Windsor brought to the Supreme Court in 2013, whose verdict declared part of the Defense of Marriage Act unconstitutional and paved the way for the full establishment of gay marriage rights two years later in Obergefell v. Hodges. Though it plays more like a production made for history museums than a theatrical film, the doc will be welcomed on video by those seeking heroes in this whirlwind civil-rights narrative.

Understanding that much of its potential audience will be too young to grasp how dramatically things have changed for LGBT people in just a few decades, Zaccaro devotes about ten minutes to a brief history of gay rights. She finds a 1967 CBS news special called The Homosexuals, hosted by Mike Wallace, that looks hopelessly square as it attempts to introduce straight viewers to the hidden minority around them. She follows that with shout-outs to early advocacy groups the Mattachine Society and Daughters of Bilitis, zips quickly through the Stonewall Riots and early Pride parades and then talks of how the tragedy of AIDS had the positive effect of forcing Americans to speak of their gay loved ones openly.

All this is backdrop for the story of Edie Windsor and Thea Spyer, who met in 1963, fell in love and decided to unofficially marry in 1967. Both were professionals and had reasons to keep their private lives private, so they exchanged diamond brooches instead of wedding rings. They didn't make things legal until 2007, when Thea (who had MS) was told she wouldn't live much longer; the ceremony was in Toronto, and they expected New York state to honor their legal union.

But when Spyer died, Windsor was hit with inheritance taxes a spouse wouldn't have had to pay, totaling hundreds of thousands of dollars. She decided to sue, and found the ideal advocate: lawyer Roberta Kaplan, who many years earlier had consulted with Spyer (a psychologist) about her own issues living as a lesbian in a straight world. Kaplan's team took on the case pro bono.

Zaccaro offers an easily digested explanation of what they were up against. We see how the Defense of Marriage Act was born out of a panic that Hawaii's inclination to legalize gay marriage would spread. The film is quick to make excuses for Bill Clinton, who as president presented himself as an LGBT ally but signed the legislation into law; he was boxed in by Republicans, we're told, and had little choice. (Um, sure. Same thing with welfare reform and the crime bill, right?)

Journalists including Nina Totenberg and Jeffrey Toobin explain how ideal Windsor's case was as a means to prove the cruelty of DOMA, and the film follows oral arguments while offering personal context for those involved. The makers of other recent docs on this subject (like last year's Freedom to Marry) might take issue with the film's emphasis, feeling it gives more credit to Windsor and Kaplan than they deserve. But they certainly won't argue with its celebratory tone, even as a new wave of challenges (like this week's ruling about Colorado cake makers) hopes to chip away at the acceptance of gay families in America.

Production company: Ferrodonna Features
Director: Donna Zaccaro
Producers: Paula Heredia, Donna Zaccaro
Editor: Paula Heredia
Composer: Wendy Blackstone

63 minutes