One photographed chairs because she rarely sat down. Another took pictures of a steaming cup of coffee because he usually worked out in the cold. And one woman clicked as her 25-year-old son got his hair trimmed because her work had kept her from seeing him get his first haircut when he was a child.

The images, stunning in their simplicity, tell stories. They are the sometimes personal, sometimes poignant and always illuminating tales of dozens of faceless janitors, nannies and day laborers given cameras by their union and urged to make pictures.

"We just don't see so many of the people who make our lives work," said Esther Cohen, creative director of Bread and Roses, the cultural arm of Local 1199 of the Service Employees International Union. "It's such an insight into the lives of all of us."

It started when Local 1199 tried to tell the stories of its growing immigrant membership. Calling the project Unseen America, the union received 100 donated cameras and organized 12-week introductory photography classes for its membership: migrant workers, home care aides, building maintenance men, garment workers and housekeepers. Each week students left with five rolls of film and instructions to document their lives. In three months, they snapped thousands of photographs of rarely seen New York scenes, some of which were displayed in the union's local gallery.

The SEIU is the nation's fastest-growing union, gaining 153,000 members in the past two years. Over that time, local union chapters nationwide have adopted the program. More than 1,500 people from Boston to Chicago have taken Unseen America classes and SEIU chapters from Los Angeles and Newark plan to launch projects. Select photographs from earlier classes are circulating at universities and galleries across the country and the AFL-CIO plans to exhibit some of these photographs in Washington next spring.

One photograph on display here in the local's office is of a gray horse nodding back at an empty carriage in Central Park.

"I am like the horse," Barbara Fu, 35, a Chinese immigrant and bill processor for the Visiting Nurse Service of New York, wrote in a narrative accompanying the photo. "I have to work whether I like it or not because I need to make a living. Everyday is the same routine until we retire or our owner/company doesn't want us anymore. I want to keep moments of life. Life passes too fast and I can not stop it even if it is a happy moment."

The Unseen America photographs reflect a bleak and lonely New York. They feature shadowy fire escapes clinging to tall Queens and Brooklyn tenements and cramped Chinatown spaces where immigrant children plod through homework. They include a Mexican laborer curled up on a sheetless bunk bed, his well-worn sneakers tossed beneath him, and the snow-covered shoes of a homesick Filipino woman.

Historians praise these dark photographs as valuable documents of contemporary immigrant life. Immigrant outsiders such as Jacob Riis and Lewis Hine took some of the most intimate photographs of New York at the turn of the last century. Most immigrant families' photographs came from Lower East Side portrait studios.

"Generally the best documentation of any group is the wealthy groups," said Kenneth T. Jackson, New York Historical Society president and editor of "The Encyclopedia of New York City." "Wouldn't it be great if we had a more complete archive of what, say, an Italian immigrant's life was like?"

For Cristina Hinlo, 68, a Filipino immigrant, Unseen America gave her what her daughter calls her first hobby besides housekeeping. Since she took her Unseen America class 18 months ago, Hinlo has photographed fellow housekeepers commuting through Long Island train stations and on weekends has snapped pictures of birds soaring over her daughter's Queens apartment. When her daughter took over her housekeeping job so she could retire, she started to photograph her senior center's monthly birthday parties and her granddaughter posing in new outfits.

"Everywhere I seem to look for something to capture," she said. "I am what you call emotionally involved."

Hinlo, whose photographs of her granddaughter and a baptism have joined the traveling exhibit, sometimes questions whether these bleak black-and-white photographs should have the title "America" in them.

"When you are in the Philippines, these are the things you don't see," she said about her classmates' work. But, she added, "these people are part of America."

Some photographs reflect the dangers of contemporary immigrant life. One Filipino nanny asked that Bread and Roses organizers not include her pictures of the child she cared for in the exhibit because she feared losing her job if the mother disapproved. A day laborer photographed Long Island community groups as they picketed him as undocumented for standing on a street corner waiting for work.

"They have total access" to the scenes that they photograph, said David Bacon, a California-based professional labor photographer and labor journalist who has chronicled immigrant lives. "They just have no rights."

For Blase Alleyne, 53, an immigrant from Trinidad and environmental services worker at the Mary Manning Walsh nursing home, it was more important to show to his co-workers the steel-drum tuners and players with whom he spends his free time rehearsing.

"I wanted them to see that besides doing what I usually do at work, there is something else out there that interests me," he said. "People on the job didn't even know I used to do this."

Alleyne, who recently finished his Unseen America course and whose photograph of a steel-drum tuner "blending a tenor pan" remains on display, hopes to chronicle his life in New York through more pictures.

"You go to certain places and see things. But when you go away you forget. Your memory fails you sometimes," he said. "When you take pictures it will be an everlasting memory."

In Unseen America, immigrant workers are given cameras and training to record moments from their daily lives. From left: In "Barbershop," the anonymous photographer, who missed her son's first haircut, captures one more than 20 years later; "Kneading Dough" by Valentina Palusaj shows only the worker's hands; and "Hot Coffee," by an anonymous outdoor laborer, takes as its subject a small daily pleasure. Rodolfo Sorto, with cameras, and Amilcar Sandoval are on the maintenance staff at a community center in Oceanside, N.Y.