Welcome to Quitman County, population 10,490.

In 1968 not long before he was murdered, the Rev. Martin Luther King, Jr. visited Marks, Mississippi in Quitman County and wept at the squalor he encountered on Cotton Row, a muddy, unpaved street in the town's black quarter.

If King were to come with Sister Joan Dunning, O.P. nearly 30 years later as she drives into Crenshaw, another hamlet surrounded by cotton fields in the Mississippi Delta, he almost certainly would weep again.

It is a gray afternoon, and the wind, still carrying winter's bite, fans flames that rapidly consume a tarpaper shack and spreads dark, greasy smoke over the other shacks in the neighborhood. Evaline, barely 20, stands mutely, her face etched with despair as she watches her meager possessions disappear. She has escaped the fire with her five children and the clothes she wears, but little else. She is lucky -- four children died in a similar tinderbox that went up in flames just the day before in another part of Crenshaw.

Dunning puts her arms around the young woman. "I'll get you all something to wear right away, even if I have to beg at Wal-Mart," she says.

Dunning is one of a small group of Dominican sisters, most of them possessing medical skills, Who have made their presence felt in northern Mississippi for the past 16 years as the DePorres Delta Ministries.

A woman of great energy and good cheer, Dunning reflects on the painful scene in Crenshaw on the drive back to her office in Marks.

"Fires are so commonplace here. It is much more devastating coming at the beginning of the month like this because Evaline has just gotten her baby formula and food stamps for the month."

Bordered by sere fields of last year's cotton, the road stretches ahead across the flat, featureless landscape of the Delta. Dunning has driven many miles on roads like this. Much of her time on the road has been spent working with young pregnant women and mothers.

"What can we do to help these young mothers break the cycle of their lives?" she asks. "Education is the key. They have to want more than they have and not settle for so little. Usually they come from homes where they've been abused. Frequently the fathers of their children are married men who dump them when they become pregnant. So they're hardened, and they have no hope because it's been shattered so many times.

When one of these girls becomes pregnant, she receives so much attention from me and from doctors at the hospital. For the first time in their lives these girls have people caring for them.

"There are moments when I get discouraged," she continues, "but then I remember that one person can make a difference. Even if I can inspire just a few girls to sat goals and become more nurturing with their children, it becomes worthwhile. It's a ripple effect. You start with one family and it spreads,into the community.

"There was a father who came to one of my parenting classes. He was there reluctantly, and I know he was saying to himself, `She hasn't had children. What does she know?'

I hadn't realized I was touching him at all, and then one day he said, `This class has changed my life more than anything. I have found out that I can be a more loving person and the kind of parent that I wanted my parents to be.' It was beautiful to hear him say that."

There is no question that the countless hours that Dunning has spent with Quitman County's adolescents have made a profound difference. Since her arrival in Marks, the infant mortality rate in this part of the Delta has been virtually cut in half.

DePorres Delta Ministries was founded in 1981 by four Dominicans from Sinsinawa, Wisconsin. One of them is Sister Marilyn Aiello, a former high-school science teacher, who began her training as a doctor when she was 39. After her graduation, she went to Quitman County because of the dire need for her services there. At the time, there were only two physicians in the entire county, and both had reached retirement age.

Almost half of the residents of Quitman County live below the poverty level. One in six adults is unemployed and only four out of ten graduated from high school. The county is without a single bookstore.

During the course of a day, 45 to 60 people pass through the doors of either DePorres' main clinic in Marks or a satellite clinic in the nearby farming community of Sledge. Mostly they are treated for the chronic diseases of poverty: diabetes, hypertension, heart disease, skin disorders.

If you are lucky enough to find her with a free second, Dr. Andrea Balconis, the Dominican now in charge of the two health centers, will tell you about the problems that she and Dr. Aiello and the rest of her staff routinely face. In all likelihood, she will be tired because both doctors are up by 4:30 every morning so that they can make rounds at a hospital 30 miles from Marks. Both are permanently on call.

"For the most part we see the needy elderly -- people who have neglected their health for years. They have no understanding of their diseases and wait until they can't function to come in. Health care is not uppermost in their minds. They take better care of their trucks."

And then there is the lengthening shadow that AIDS casts over the Delta. HIV patients come to Marks from nine neighboring counties and Balconis' caseload is approaching 100. In the past two years she has watched 19 of her patients die of the disease.

"A representative from a drug company visited us to see why so many prescriptions were coming from Marks," she says. "He was surprised to find us in a town with no traffic light, on a street with no name, and in a building with no number. He said this place lit up his computer. Usually he only visits city hospitals."

One of Balconis' AIDS patients recently traveled from a distant part of the state to keep an appointment with her. "When I asked him why, he said he had called 23 doctors, but when they learned of his diagnosis, they told him either they did not take AIDS patients or were not taking any new patients. He called the state health department, which said DePorres Health Clinic would not turn him away."

DePorres Delta Ministries, named after Saint Martin DePorres, a 16th-century Peruvian monk known later as the Saint Francis of the Americas, concentrates its energy and limited resources on children as well as seniors and HIV patients.

As happens in so many small towns, the children of Marks are left at loose ends after school. Larry Smith, a local minister who is assistant director of DePorres Social Services, has solved part of the problem by attracting a noisy group of kids every afternoon to his office. He feeds them a snack and helps them with their homework on two ancient computers one sister wryly calls a "computer museum."

Sister Selina Stanaway, director of DePorres Social Services, spends this March morning with three college students who have come to the Delta as Apostolic Volunteers during their spring break. They spend time with local children at a Youth Fair inspired by Smith, as well as washing windows for an elderly woman in Marks who stands outside her small house, despite a gentle rain, and watches the volunteers work.

"Like so many here, she can't read," Stanaway says. "These women are very conscientious about paying their bills, but if they can't read, it's hard. They come in not knowing if they have a bill or an ad."

Like the other Dominicans, Stanaway has found the going difficult at times in the Delta. "There have been ups and downs and curves in the road, but I give thanks for all of these experiences. The gospel teaches that we are nourished by sharing with one another."