During the summer of 1971, Michael Lesy was staying with a friend, who was a motorcycle delivery boy who ferried film from drugstores to be processed at a factory. 'Every week, for four weeks during the summer, we took home whatever snapshots we found. They were in the trash because the machines that made them—duplicates, triplicates, quadruplicates—made them faster than the people on the line could stop them,' he wrote in his new book, Snapshots 1971-77. In the image above, Lesy noted the man's holster and his gun, and that he was likely a detective. 'Look beneath the surface,' Lesy told DailyMail.com, 'that is what this book insists upon'

Lesy estimated that he took home around 7,000 images a week. 'I'd spend days looking through them. Some I kept; most I threw out,' he wrote in Snapshots 1971-77.  When he went back to graduate school in Wisconsin after that summer in San Francisco, he took hundreds of snapshots with him. He told DailyMail.com that he was very selective in editing. 'I understood them as forming an archive—an archive of the present,' he wrote in his new book. Above, a wedding couple with Lesy noting the groom's foxy grin

Vacation pictures used to fill albums instead of social media platforms. Lesy noted the body posture of the family above. 'The boy is having none of this,' he said, adding that his mom links her arm with his anyway. The daughter is holding herself up and she leans against her father. He wrote in Snapshots 1971-77: 'I realized something important: the people who made the pictures were insiders, not outsiders. I also understood that the people behind the camera made, without intending to, pictures of themselves'

'It's like a Madonna, I thought,' Lesy said about the image above of a young mother with her baby. The snapshots that he found either because they were never picked up or because they were duplicates offered a look into his fellow citizens' lives. 'Looking through the snapshots, fresh from the trash, was like being blasted by a firehose of information, soaked and pinned to the wall by it. It was intimate, domestic, close-up information that I could never have known otherwise,' he wrote in Snapshots 1971-77

Above, three well-dressed men at a party and Lesy noted the dignity and formality of the image. After that summer in San Francisco, Lesy took hundreds of snapshots and went back to graduate school in Wisconsin. While studying American history, he met Paul Vanderbilt, an archivist and photographer. Vanderbilt told him about an archive for a town called Black River Falls. It included images taken by photographer Charles Van Schaick. This became Lesy's dissertation, which would turn into his first book, Wisconsin Death Trip. 'It was very controversial,' he said of his 1973 book

Lesy said the above picture of a man smoking weed in front of the U.S. Capitol is 'a protest photograph. It's a rebellious image.' In 1971, the United States was still embroiled in the Vietnam War and the trials of those involved with the 1968 My Lai Massacre and the shocking 1969 murders of actress Sharon Tate, who was pregnant, and others at the hands of Manson's followers, were ongoing

'Every picture has a backstory – has a surface and a depth,' Lesy said about the snapshots. He pointed out the written reminders on the chalkboard behind the nun in the above image. In addition to photographs taken during the Great Depression in the 1930s, Lesy was also inspired by Henri Cartier-Bresson, a famous photographer known for the 'decisive moment' and one of the founders of Magnum, and an important 1955 Family of Man exhibition at the Museum of Modern Art. He told DailyMail.com: 'I was carrying those in my head'

Lesy said that some of the images in the collection were obscene. He noted that when a person took their negatives to a drugstore or another business, like a Fotomat, to develop the film, there were times when they refused to print the photo. The image above, he said is very sweet, loving, affectionate and erotic. He noted that it seems she created mise en scene and all that was missing was a bear skin rug

There are several rituals that have changed around photography since the ubiquity of cameras on phones and the arrival of other technology. Lesy noted that families used to sit down with albums to talk about the photographs and the past. For example, a child might ask a parent who someone is in a photograph, he explained. 'What they leave out is often as important as what they leave in; what they emphasize and what they minimize can be equally revealing,' he wrote in his new book, Snapshots 1971-77, about the images. Above, kids wearing pirate hats at a birthday party

Lesy said the snapshot above reminded him of the 1990 movie Goodfellas. He wondered who was taking the picture and if it was law enforcement. Lesy told DailyMail.com he was a self-taught photographer and many people were picking up a camera while he studied at Columbia. 'It was in the air.' He carried a 35mm, single-lens reflex camera and aspired to be a documentary photographer. Lesy has written 13 books, some of which are based on archival photography, like Wisconsin Death Trip

In the late 1970s, Lesy was back in his hometown of Cleveland and another opportunity for snapshots cropped up. Through a friend, he met a drugstore owner who didn't know what to do with the pictures people did not pick up. 'Drugstores in Cleveland threw away unclaimed snapshots after several weeks of waiting for customers to pick them up. I never found out if the drugstores had an official time limit,' he wrote in Snapshots 1971-77. 'I suspect that when they ran out of space to keep them behind the front counter, they threw the pictures into a bag and—once the bag was full—threw the bag away.' Above, a 'very hip' woman, Lesy said

Above, likely a Memorial Day celebration, Lesy said. 'Seen through the eyes of an outsider like me, the snapshots looked in four directions at once: out at the subject, back at the photographer, inward at their assumptions and beliefs, and then out, beyond them, at the world in which they thought they lived,' he wrote in his new book

'I always had it together,' Lesy told DailyMail.com. 'This book could have been made at any time.' However, he noted there was more of a legal risk if he published before now. 'Times changes everything,' he said. Above, the cover of his book. Lesy explained that after Wisconsin Death Trip, which sold well, he wrote more books. 'For the next twenty years, from one book to the next, I traveled throughout the United States giving lectures, each illustrated with hundreds of archival images. I don't remember when I made color slides of the snapshots I'd found in San Francisco. Now and then in my travels, I'd show them to audiences,' he wrote in Snapshots 1971-77. 'The purpose of those slide shows—and now the purpose of this book—was to show images whose meanings appear obvious, but which are riddles with more than one answer'