In a tearful drama at the Jenkins County Courthouse, Kathleen Blackburn was reunited today with her 3-year-old son, Nicholas, a blond-haired child taken from her 18 months ago by a local judge after she gave birth to a racially mixed daughter.

Last week, the Georgia Supreme Court ordered the boy's paternal grandmother, Nancy Blackburn, to surrender the child in a custody battle that has pitted civil rights activists against the ways of this small town.

Earlier, the court had paved the way for the reunion, overturning a ruling by Superior Court Judge Colbert Hawkins who had given the grandmother custody.

Beneath a granite statue of a Confederate soldier, Kathleen Blackburn, 27, ran a gauntlet of lawyers, police and television cameras to take the child she has not seen in 18 months from the arms of her former husband.

Said Mark Blackburn, Nicholas' father: "I feel like I've been cut by a knife."

"Come here, Nick," cried Kathleen Blackburn, clutching the shaken child. "Oh, my baby. Oh, my baby." Her toddler daughter, Jenifer, gleefully patted her brother, oblivious to the fuss.

Today's emotional meeting was the latest round in an 18-month legal battle that has raised charges of racism and small town injustice.

Kathleen Blackburn claims she is fighting racism to raise her son. Her ex-husband and his parents say it's a question of where Nicholas can get the better care.

"Every time we told him he was going back to his mother, he hid in the closet," said his grandmother, clutching Nicholas' Smurf doll and toy dump truck. She vowed to help get him back.

Lawyers for Mark Blackburn will take their case to another custody hearing, scheduled for Dec. 1 -- Nicholas' fourth birthday. Hawkins, a hometown hero under fire by black civil rights leaders, is expected to preside.

Kathleen Blackburn was given custody of Nicholas after she was divorced from the boy's father in 1979. By her account, she had an affair with a black ex-Millen police officer, who acknowledged being Jenifer's father.

Six weeks after Jenifer was born, Blackburn's former mother-in-law successfully petitioned for temporary custody of Nicholas. In her petition, she charged Kathleen 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. There was no hearing.

At the trial, witnesses testified that Blackburn neglected her son, and a clerk in the motel where she once lived testified that she came and went at all hours with Nicholas in tow. Others testifed that she was a good mother. Hawkins awarded permanent custody to the grandmother; the Georgia Supreme Court reversed him.

Shunned by the white community here, Blackburn moved to nearby Waynesboro, where she works in a record shop. Most of her friends, she says, are black.

Represented by Georgia Legal Services attorneys, Blackburn said she could not afford the $2,000 visitation bond imposed by Hawkins, so did not seen her son until today.

She said last winter she received a check for $2,500 as an advance for her life story from Post-Newsweek Productions, Inc., a film subsidiary of The Washington Post Co. Blackburn's lawyer, Ozell Hudson, said Saturday, however, that Blackburn had not received any money and will not until the case is settled.

Mark Blackburn, 24, once unemployed, now works as an apprentice electrician and has remarried. His one-year suspended sentence for a 1980 conviction on aggravated assault is behind him. "I like to been drove crazy by all this," he said. "It's not a racial issue, it's a human issue."