Kathleen Blackburn came to the South from Minneapolis, hoping to make a fresh start with her husband, Mark, in the sleepy town amid rolling pine forests and cotton fields where his parents lived.

But Mark couldn't find work right away and the couple fought. The marriage fell apart and they divorced in July, 1979. Kathleen Blackburn was granted custody of their son, Nicholas, and tried to make it on her own. She lost her job as a dietitian in the county hospital, and found work plucking chickens for $3.40 an hour. She fell in love with another man. A daughter, named Jennifer, was born last May.

Now she finds herself alone, fighting the town and the courts. Last month, a state judge awarded permanent custody of her son to her former in-laws. He let her keep her daughter.

Her son is white. Her daughter is black.

"I love my son and I'll fight them until the day I die to get him back," vows Blackburn, 26. Ostracized by the white community, she now lives in a black low-income apartment complex. She has joined a black church and plans to be baptized. The black community has taken her under its wing.

"This town is 100 years behind the times," she says. "It's like plantation days. I'm treated like a criminal and I haven't done anything wrong, except by Millen's standards."

Kathleen Blackburn's case underscores how America's changing moral standards have bypassed places like Millen. Blackburn believes she was cheated of her rights as a parent by the rigid codes of a small southern town and its own brand of justice.

By Blackburn's account, she had an affair with Gene Wright, a nine-year police veteran and the first black hired on the city's force. By a coincidence not uncommon in a town this size, Wright was the policeman who arrested Mark Blackburn twice, once for allegedly stealing tires (no charges were pressed) and once for aggravated assault (he was fined $250 and given a suspended sentence).

The romance was carried out discreetly, Kathleen Blackburn testified at the custody hearing, but she got pregnant. She then learned the policeman was married. Wright was separated from his wife at the time, he recalled in a recent interview, and Blackburn kept bringing her troubles to him.

"I have no regrets," he said in a recent interview. "But I'm back with my wife and three children now."

Blackburn decided to have the baby because she doesn't believe in abortion, and she refused to give up Jennifer for adoption. She didn't want her to learn one day that her mother had rejected her because she was half-black. Besides, she says, "I love my daughter."

Superior Court Judge W. C. Hawkins insists race had nothing to do with his ruling. "I looked to the best interests of the child," he said in an interview. "If she's consorting around and having babies out of wedlock, the grandparents are better off taking care of it . . . doesn't matter what color the second baby is."

But Kathleen Blackburn and her lawyers don't understand why Hawkins didn't take her black child after he declared her unfit to care for her white child. "Georgia law says the illegitimate child belongs to the mother," Hawkins explains. "She can do what she wants with it."

One of her lawyers, Lois Goodman, an attorney with Georgia Legal Services, calls the ruling an example of "racial discrimination that is repugnant to the 14th Amendment." The Georgia Court of Appeals has declined to rule on the case, and Goodman plans to seek a hearing before the Georgia Supreme Court.

These days, Nicholas, a blond, blue-eyed 2-year-old, plays happily in front of the TV set at the house of his grandparents, Bowie and Nancy Blackburn. His mother hasn't seen him since Sheriff L. C. Williams knocked on her door June 25 with a court order granting temporary custody to her former mother-in-law. That was six weeks after Jennifer was born. Faye Martin, a circuit judge in nearby Statesboro, ordered the child's immediate removal based on a petition from Nancy Blackburn.

According to Kathleen Blackburn and her attorneys, there was no hearing or notice of any kind, and that is one of their grounds for appeal.

In the petition, her former mother-in-law charged Blackburn with giving birth to an illegitimate, "racially mixed child," being a "lewd" woman and failing to set a "moral example" or provide a stable home life for Nicholas.

After temporary custody was awarded to her, Nancy Blackburn claimed Kathleen was plotting to flee the state with her son, and Judge Martin ordered her to post a $5,000 bond if she wanted to see Nicholas. But his mother never got to see him. She had just filed an affidavit of poverty with the court. She didn't have a cent.

Her attorneys asserted during the permanent custody hearing that it was illegal for Martin to ask for such a bond, given the poverty affidavit. The permanent custody ruling makes no provision for Blackburn to see her child.

Ozell Hudson, an attorney with Georgia Legal Services who represented Kathleen Blackburn at the brief permanent custody hearing last month, was shocked at the outcome. The evidence against his client hardly seemed to support a finding of neglect, he said.

At the hearing, one witness, a motel night clerk, testified that Kathleen kept late hours, coming and going after midnight with Nicholas in tow from the Congress Inn, where she lived briefly after her divorce. A social worker reported "numerous" roaches in her kitchen, but praised her ability to raise her children on limited finances. A cashier at the local supermarket testified Blackburn bought nutritious foods and dressed Nicholas in clothes appropriate for the season.

Another witness, a local doctor, Virgil Abreau, blamed Nicholas' respiratory ailments and low rate of weight gain on his mother, testifying that she had let him play on the cold linoleum floor at the hospital cafeteria where she worked. But in an interview yesterday, Abreau said that Blackburn had "tried to do her best" to take care of Nicholas. "She took the baby to my office many times when he was sick," he said. "She worked hard at her job."

Abreau said he couldn't blame what he termed the child's low rate of weight gain and frequent colds solely on the mother "because I don't know how she managed the situation at home." He said "it wasn't right" that Blackburn sometimes let the child sleep in the car while she worked or on a towel or sheet on the hospital kitchen floor.

In a written addition to the court record, submitted to the judge before he made his custody ruling, Kathleen Blackburn's attorneys maintained that Abreau had flunked the state medical exam twice and that he practices with a provisional license. In a deposition for the defense, an Atlanta pediatrician and professor at Emory University Medical School reviewed Nicholas' charts, found his weight gain normal and chided Abreau for overprescribing antiobiotics.

So it went. One witness, Angela Durden, 27, a black woman whose children played with Nicholas, said in an interview that she was threatened by an unidentified man on the phone before the hearing. "He said, 'Don't testify for her in court or you'll be sorry,' " she recalls. She testified anyway. "Nicholas was fed right," she says. "Kathleen was a good mother . . . a real nice person who was done dirty because she associates with black people."

Indeed, Blackburn touches a raw nerve in this town. Many whites hail Judge Hawkins' ruling, which one lawyer familiar with the case said "would square with the feelings of the community."

But most blacks "think it's wrong to take away her white child just because she had a black baby," says construction worker Clifford Mosley, former president of the local NAACP. He ticks off half a dozen local blacks fathered by whites and shakes his head. "Sometimes, white people are just plain crazy."

Gene Wright remains sympathetic to Blackburn's plight, having faced discrimination himself. While on the force, he says he was routinely scheduled for duty on Christmas, which meant he could not attend the department party. He left the force for a better-paying job with Southern Railway.

Some call it a sign of racial progress that neither Blackburn nor the father of her child has come to a violent end in this town of 3,900 where some residents still find civil rights laws hard to swallow. Blacks recently complained to the Justice Department that they could not be served at a green cinderblock beer joint called the People's Choice, which is now shut down. The department is investigating.

"A lot don't like it a black man with a white woman , but they didn't run her out of town," said the Rev. Maurice Crowder, minister of the Millen Baptist Church, which Blackburn attended before Jennifer was born. "Let's face it, this is a small southern town. It's just not ready to accept such a ticklish situation."