Portfolio: America's most unwanted

For more than 30 years, Mary Ellen Mark has been photographing the frayed and tattered fringes of human life. As she said in an interview for Vogue: "Well, aren't you interested in what's less normal?" She is part of America's great tradition of documentary photography, her pictures having been compared to those of W Eugene Smith, Margaret Bourke-White and Dorothea Lange - and there is a little of Diane Arbus, too, in the luminescence of her prints. Although her approach is different from any of her predecessors, she reflects those pioneers who cared deeply, who could not help but become involved and who lash us to their vision of a world gone wrong. She worked for Life when that meant something, she has been commissioned by Time, and occasionally, over the years, by The Independent Magazine. Now in her 50s, she is perhaps the most celebrated documentary photographer of our time.

Next to this, her work for the shinier end of the market - Vanity Fair, American Vogue and others - sometimes sits a little uncomfortably. One critic for the Washington Post could see only surface gloss in her pictures: "Everywhere she goes, her lighting is just right." An article in Vogue listed the equipment she took on the trail of an Indian circus: four Nikon FM2s and seven lenses, four Leicas and five Leitz lenses, one Polaroid SX-70, four Hasselblads, strobes and light meters - she also used a thousand rolls of film. The days of the lone documentarist in the dustbowl were truly over, but the means always justified the end, and, especially in the early days, the celebrity portraits clearly financed another trip to the brothels of India or kept her with the street boys of Khartoum for a just a few more days. Her pictures show that she belongs out there with the overlooked and marginalised.

In 1977, Mark joined Magnum, the agency founded by Henri Cartier-Bresson. Association tends to be for life, but hers lasted only five years. She felt she would be better off on her own - one suspects she can take direction only from herself. There are fewer documentary commissions these days, and she has become increasingly aware of the power of the single image rather than the photo-essay. "I am always thinking about pictures that speak for themselves," she has said. Her new book, American Odyssey, is published by Aperture this month; its accompanying exhibition shamefully without a British venue. Hers is a unique and disquieting oeuvre, and her journey across America has been, she says, "an incredible adventure. You can find everything in this country - anything goes, anything can happen."

`Mary Ellen Mark: American Odyssey', is published in the UK this month by Aperture Publishing, price pounds 31.25

`Crissy, Dean, and Linda Damm', Llano, California, 1994 One of Mark's most celebrated images, from the series "The Homeless Family," this shot stands alone as an eloquent study of desperation and exhaustion. She photographed the Damm family twice, first in 1987 and later in 1994. Both times were pivotal in the family's lives. On the first occasion they had just been thrown out of a shelter and, though they were sometimes housed in a motel for the weekend, they stayed mostly in their sedan car. Eventually they were admitted to a temporary shelter, where Crissy, clearly traumatised, lay in a foetal position in the shower. Seven years later, their fortunes had not perceptibly changed. Jesse and Crissy, the two kids, were not attending school and there were now two more, Ashley and Summer. Here they are squatting in an abandoned ranch. Mark is still in touch with them. Recently Dean and Linda split up. Crissy is now 18 and writes poetry.

`Vera Antinoro, Rhoda Camporato, and Murray Goldman', Luigi's American Italian Club, Miami, Florida, 1993

Mark scours as many newspapers as she can in a quest for the unusual, and at one point she employed a team of researchers to help her find stories. To her, the most interesting concern is ordinary people - "the unfamous", as she calls them - and the best essays come from the periphery of the American dream. "This is part of a project on men who dance with women for money. The men are not quite gigolos, more paid male escorts, I suppose, and the women, well, they are widowed or single or lonely. The guys learn to be great ballroom dancers. I used a large format camera, pre-focused it and prayed that something would work."

`Leprosy Patient with her Nurse', National Hansen's Disease Center, Carville, Louisiana, 1990

Held in the vast arms of her nurse, the shrunken leprosy patient appears like an alabaster saint. This is one of Mark's most famous images. It was part of a story commissioned by Life magazine but, in the end, it never ran. "I went in," she recalled, "and asked permission and took the picture. You have to be direct. If you don't ask, you lose. If you feel intimidated you lose. People have to give me something, let me see something that's personal. It's not the glittery thing of having a concept." About her reportage, which she admits is not often easy on the eye, she once said: "I don't take pictures to put in a box. I want as many people to see them as possible."

`Amanda and her Cousin Amy', Valdese, North Carolina, 1990

Mark has said that her first proper and successful photograph was a portrait of a young street girl taken in the mid-Sixties in Trabzon, Turkey. In a wrinkled dress with a bow in her hair, her cheeks sucked in like the model she will never become, the futility of her never-to-be-realised dreams and the photographer's palpable tenderness characterise the best of Mark's reportage. A quarter of a century later comes Amanda, another girl mimicking the gestures and postures of someone far beyond her years. "She's smoking a cigarette, she's on the edge. She's my favourite. She was so bad she was wonderful. She had a really vulgar mouth. She was brilliant."

`Sherry Collins Eckert with Madame Butterfly', Afton, Missouri,1995

This portrait was taken for Allure, a sister magazine to Vogue in the US, which deals broadly with beauty and health issues. Mark's story on this occasion satisfied both criteria. It concerns the National Association to Advance Fat Acceptance. "I travelled around photographing these women. I went to one of their parties." This was the Big and Beautiful New Year's Eve party held in Long Island in 1995. "They were quite militant and felt discriminated against. They have a right to protest." Sherry's cat was "quite big, too" and its name perfectly in keeping with the larger-than-life themes. "It's quite operatic," says Mark.

`Mona, Angry', Ward 81, Salem, Oregon, 1976

Mark worked for expenses only as the stills photographer on Milos Forman's One Flew Over The Cuckoo's Nest, filmed at a mental institution in Oregon. The director of the hospital took her round the facility. Mark was determined to return and to photograph Ward 81, a maximum-security unit for women considered a risk to themselves and to anyone else who ventured in. It took a year for Mark to gain access again with a camera and a writer. She spent over a month there in 1976, observing shortly afterwards that "the women had very strong personalities. Some of them were funny, some romantic, some social. You could label them just the way you might label your friends ... the difference was that the feelings were so much more exaggerated. There's no bullshit - the emotions are pure." The Ward 81 project became a book which Robert Hughes, then art critic at Time, described as "one of the most delicately shaded studies of vulnerability ever set on film."

`Diamond Settles, Halloween', South Bronx Help Shelter, New York, 1993

Mark likes the rituals and rights of childhood. The portrait of a costumed Diamond Settles was taken for a project on a shelter for the homeless. Mark spent an entire summer there. "I wanted to come back and see how they celebrate Halloween as I had heard them talk about it. I saw this woman going back into her apartment with a screaming child - she was frightened of the other Halloween costumes, I think. Her mother put her in the bathroom to calm down." Dressing up and disguise play a big part in her oeuvre, her subjects frequently yearn to be something other than they are, or to transcend, for a moment, the circumstances they find themselves in. On other occasions, disguise was a condition of the assignment. Once, for Esquire magazine, she photographed some "swingers" who wished to maintain their anonymity. "I love the idea of disguise," she says. "I photographed the Lone Ranger once."

`Bull Riders Craig Scarmardo and Cheyloh Mather', Boerne Rodeo, Texas, 1991

This shot was from a series on bull riding for Texas Monthly. "This was taken at the end of the trip," she says. "It is a very violent sport and difficult to witness - a bit like bullfighting. As tough and macho as you can find. I feel it's important to take photographs that reveal who people are. I always try to hit on something personal and revealing, when you get that openness. Ordinary people are so much more willing to reveal themselves." `Jennifer, Tiffany and Carrie', Portsmouth, Ohio, 1989

Children with nothing or very little have played a large part in Mark's photographic vision - none more poignantly, perhaps, than street children, whether in Falkland Road, Bombay's red-light district, or in Khartoum where she found many addicted to glue. In American Odyssey, they appear to swarm in droves to her camera and she to them: deaf and blind children in Massachusetts, pageant winners in South Carolina, twins conventions, children playing as gangsters in Dallas, teenage mothers in Portsmouth, Ohio. She is touched by kids who have no advantages: "They are much more interesting than kids who have everything. They have a lot of passion and emotion." And, presumably, a strong will to survive. She has added that we have to let them live their lives, which is, she says, their right: "You can't force people into a lifestyle they don't want. As terrible as you might feel their lives are - and maybe they are that terrible - it's their lives."

`Tiny in her Tub', Seattle, Washington, 1999

With her husband, the film-maker Martin Bell, Mark made Streetwise, a celebrated documentary on teenage runaways and survival on the streets of Seattle. It's "star" was Tiny, who lived rough to avoid her alcoholic mother. She was 12 then (in 1983), in and out of trouble with the law. "She was completely candid and open in front of the camera," Mark says, "except for the first time I saw her and took her picture in a parking lot - she thought I was the police, screamed and ran away." Eighteen years later, Mark found her again, though they had kept in touch sporadically - whenever Tiny needed bail money, mostly. At one point, the couple considered adopting her, which she wanted desperately, but not enough to fall in line with the conditions Mark and Bell laid down. "She is now a single mother with five children, all by different fathers. Her life is so difficult. She tries hard to make it work and yet she essentially lives on welfare. She still has many dreams, but they are not as grand as they were when she was 12."