Bronx-born photographer Alvin Baltrop spent days on end documenting gay life at the piers lining Manhattan’s west side. At times, he did so while living in a van. Now, his intimate imagery, mostly unseen, is finally receiving the attention it deserves in a new exhibition at the Bronx Museum of the Arts in New York.

In The Life and Times of Alvin Baltrop, which opened last week, over 200 photos from his overlooked archive shed light on the city’s gay culture of the 70s.

“Alvin photographed the LGBTQ community differently than Robert Mapplethorpe, who shot them in a very explicit and glamorization of the S&M culture,” said Bronx Museum curator, Sergio Bessa. “Baltrop wasn’t about that. He saw sexual freedom.”

Baltrop photographed the westside piers of Manhattan, today where the multi-million-dollar Whitney Museum resides. When a nearby highway collapsed in 1973, it took the city roughly a decade to fix it. “There was no money to fix anything, the highway stayed like that for ten years,” said Bessa. “It’s a different reality of what that area looked like in the 1970s and 1980s, compared to now.”

His pictures show the time following the Stonewall riots and before the Aids crisis. Pier 48 was an abandoned wooden structure where gay men sunbathed, cruised and hooked up outside of the glittery world of disco and Studio 54.

The Piers (exterior) Photograph: Courtesy of The Alvin Baltrop Trust

“He documented a place where people could go to hook up and have sex in a public space,” said Bessa. “People say ‘that happened all the time,’ but not the extent as it did in the 1970s. In the wake of counterculture, the end of hippie culture, social norms were changing, and this was happening at a global scale.”

Baltrop, an African American photographer, was born in the Bronx in 1948. His mother was a Jehovah’s Witness who despised his photos and threw out his artwork when he was a teenager, which led him to moving away from home. He served in the Navy during the Vietnam War in the 1960s, where he took some of his early portraits of sailors. He was just 21. “He took them with the eye of a gay or bisexual man acting out on his desires,” said Bessa.

He returned to New York to study art from 1973 to 1975, which led him to documenting the gay community in the West Village and along the piers from 1975 to 1986. However, it wasn’t just a study of architecture.

“Although initially terrified of the piers, I began to take these photos as a voyeur [and] soon grew determined to preserve the frightening, mad, unbelievable, violent and beautiful things that were going on at that time,” Baltrop once said.

His work, on view until next February, has been compared to photos by Robert Mapplethorpe, Peter Hujar, and Gordon Matta-Clark, who made artwork at the very same set of piers. They also take a snapshot of a city in ruin, and a queer community struggling for inclusion. Through the 1970s and 1980s, Baltrop shot nude men sunbathing along the Hudson River and a stunning portrait of activist Marsha P Johnson.

But Baltrop struggled to make a living and among his odd jobs, he worked as a jewelry designer, a street vendor and a cab driver. “He was a very poor man, he sustained himself driving a van, was a street vendor, he had a difficult life and photography was a passion, a labor of love. The photos are what they are.”

Marsha P Johnson by Alvin Baltrop Photograph: Courtesy of The Alvin Baltrop Trust

He only had a few exhibitions in his life, one at a gay nightclub. Baltrop, however, gained critical acclaim after Artforum critic Douglas Crimp wrote about his work in 2008. “I don’t think Baltrop saw photography as a career, let’s say he saw it as a passion,” said Bessa. “He had a sophisticated eye for black and white photography and most of the photos here are vintage prints he developed himself.”

The photos were not always taken care of in an archival manner. They were spread across his home in piles – some spilling onto the floor. “When people would come over to his home,” adds Bessa, “Baltrop would tell them to ‘catwalk through the photographs’. This isn’t something a professional photographer would say.”

His images ranged from men having sex (shot from a distance) to homeless friends who lived onsite. He also photographed random New Yorkers on their daily strolls, the graffiti and the police surrounding crime scenes.

Though people were scarcely documented on the site, they sometimes had an air of loneliness to them. “Sometimes he’d photograph a solitary man holding a bag, or people looking for each other,” said Bessa. “He didn’t pry on people. They’re often shot from far away, which makes the photo more interesting.”

There are also a lot of architectural photos, too. Pier 52, where he took many of these photos, was demolished in 1983. “His photos outlived the structure,” said Bessa. “There’s a thorough documentation of the site, which is fascinating.”

Photograph: Courtesy of The Alvin Baltrop Trust

He fell in such deep love with photographing the piers that Baltrop sold his cab and bought a moving van, which allowed him to work less. “In his off time, he took photos at the piers,” said Bessa. “He had a lot of trouble to pay his rent, he was a bouncer at a gay club in the East Village, he really struggled to survive.”

It wasn’t frowned upon having a side hustle, however. “We now live in a time of affluence and things, but in the 1970s, the city was falling apart,” said Bessa. “People did whatever they needed to do to survive.”

The loneliness in the photos translates into a stark minimalism in the photos, which symbolize the simplicity of New York back then. “The 1960s and 1970s were tough and brutal,” said Bessa. “He cared for homeless men in the piers who were kicked out of their homes. He got young men to test for STDs and gave them relationship advice. He had this caring side of him.”

Similar to Johnson, a force behind the Stonewall Uprising of 1969 who recently had a monument raised in her honor, it has taken 40 years for Baltrop’s work to be recognized, which is long overdue. But this could very well be the beginning.

“This is an archival exhibition,” said Bessa. “Hopefully someone will do a bigger show with better prints in the future. They tie into the history of New York and queer culture, but his work was much bigger than just that, this is only a small fraction of his photos.”