Image copyright ONE Archives at USC

Decades before gay marriage became legal anywhere in the US, same-sex couples were committing themselves to each other in front of friends and loved ones. Few records of these ceremonies existed - until now, writes Jonathan Berr.

In 1957, a man dropped off a roll of film at a pharmacy in Philadelphia. But the developed photos were never returned to their owners.

The pictures appear to depict a gay wedding, nearly 50 years before same-sex marriage was legal anywhere in the US and almost 60 years before it became a federally-recognised right.

Now, a trio of gay producers and writers are trying to identify the grooms to learn their story and to find out whether a pharmacy employee balked at providing the snaps because they objected to their subject.

The writers are documenting their efforts in a reality show The Mystery of the 1957 Gay Wedding Photos.

The programme, which doesn't yet have a platform to call home, is being produced in conjunction with Endemol Shine Group, whose shows include Big Brother, The Biggest Loser and Extreme Makeover: Home Edition.

Image copyright ONE Archives at USC

"It's a passion project for us," says Michael J. Wolfe, a Los Angeles-based writer. "We are turning over every stone, interviewing dozens of people in the Philadelphia area and beyond, and consulting with investigators, historians, and experts across many different fields."

The photos were acquired by a collector a few years ago who had bought them at an online auction. He realised their significance and donated them to ONE Archives at the USC Libraries in Los Angeles and at the Wilcox Archives in Philadelphia.

The couple in the pictures appear to be in their 20s or 30s, so they would be in their 80s or 90s if they were alive today. The grooms and their guests are dressed up in dark suits with flowers in their lapels.

The celebration took place in a modest flat with the blinds drawn. It featured a ceremony officiated by someone who appears to be a member of the clergy. The grooms are shown kissing, cutting their wedding cake and opening presents.

Image copyright ONE Archives at USC

Mr Wolfe and his partners, filmmaker PJ Palmer and TV writer/producer Neal Baer, have not identified the mystery couple yet.

They request any tipsters to contact them through their website and Facebook page.

Image copyright ONE Archives at USC

For Palmer, the pictures were especially moving.

"We are recovering amazing, important stories all sorts of them... and more gay history that's been buried," he says.

"There is a very rich history that's been suppressed… I wish as a child [that] I had seen family photos of a marriage like this... I would have felt more normal as a kid. I would have known that I was okay."

Couples who fell in love sometimes committed themselves to one another in unions that were not acknowledged by either governments or religions.

The US Supreme Court didn't recognise the right for gay people to marry the person of their choice until 2015, 11 years after Massachusetts did so.

Image copyright ONE Archives at USC

"We don't know how common or uncommon it was for couples to hold ceremonies to marry each other [because] there is so little photographic or film record of how people actually lived," says Eric Marcus, host of the Making Gay History podcast.

"It's important to remember that people found ways to live their lives quietly away from the prying eyes of the straight world."

Of course, that was easier said than done.

Image copyright ONE Archives at USC Image caption Wedding guests at the mystery wedding

Several years before the wedding took place, President Dwight Eisenhower signed an executive order banning gays from working for the federal government.

In 1952, The American Psychiatric Association classified homosexuality as a "sociopathic personality disturbance" in the first edition of its Diagnostic and Statistical Manual (DSM), the listing of known psychiatric disorders.

After considerable lobbying by activists, the APA removed homosexuality from the second edition of the DSM in 1973.

The Stonewall Riots, considered to be the birth of the modern gay rights movement, had happened a few years before that in 1969 - 12 years after the wedding.

Image copyright ONE Archives at USC

It's not just the passage of time that will hinder the search for the grooms. The filmmakers believe the Aids crisis may also be factor - about 700,000 Americans have died since the start of the epidemic in the 1980s, according to the Kaiser Family Foundation.

"We are talking about a generation of people who were decimated by Aids," Mr Wolfe said. "There are a lot of missing people who otherwise would have made a search like this much easier. All of that happened before social media."

If the couple is ever identified, they would certainly add another chapter in the history of gay rights for doing something extraordinary that is now becoming increasingly ordinary.