Ruth McKay and her daughter-in-law had been at odds for a decade, ever since the day McKay flew from Florida to Maryland to urge her son, Michael Sagalow, to put off his wedding. He had given up trying to mediate between them, convinced that his mother would never accept the woman he had chosen to marry.

But when McKay's granddaughter Zoe was born in April 1996, it seemed that everyone might finally put aside their grievances. McKay called her son and his wife, Sarah, to congratulate them and sent a $1,000 check. The Germantown couple responded with friendly thank-you notes. Michael, who hadn't spoken to his mother in months, resumed calling her regularly.

Fifteen months later, though, McKay had yet to meet Zoe and the Sagalows wouldn't set a date for a meeting. So McKay hired a lawyer and sued under Maryland's grandparent visitation law.

That touched off a legal battle that made the family's earlier clashes seem mild. Before it was over, McKay's son and daughter-in-law would accuse her of shoplifting and adultery, and a court opinion would find that the Sagalows suffered from "delusional thinking bordering on paranoia."

Both sides agree that they are much worse off now than before the lawsuit. McKay still has never seen Zoe, and the Sagalows are estranged not only from Michael's mother but from his three siblings and their families as well.

"There isn't a day I don't think about what I could have done differently," said McKay, 76, who says she spent $13,000 on her unsuccessful lawsuit.

"If this is winning, I hope never to win like this again," said Michael, 46, who spent $10,000. "This is a total nightmare for everyone who has gotten involved."

When the U.S. Supreme Court took up the issue of grandparent visits this month, the justices focused on high-minded principles: the constitutional rights of parents to raise their children without interference vs. grandparents' deep bonds and blood ties to the next generation.

But the battles aren't usually fought on that elevated plane. Lawyers, psychologists and participants say that, in practice, grandparent visitation cases are vicious family disputes that dredge up old wrongs, force neutral parties to pick sides and damage children by thrusting them into the heart of adult conflict.

"Often [these cases] are not about legal issues. It's an enactment of ongoing issues within the family," said University of Virginia psychologist Robert Emery. "If there wasn't an opportunity for a court battle, families would be forced to work things out on their own."

Many lawyers and psychologists argue that visitation lawsuits should be limited to cases where the child already knows the grandparent well.

"You shouldn't put the kids through that process unless there's some kind of legitimate connection," said Sanford Ain, a D.C. lawyer who filed an amicus brief in the Supreme Court case asking the court to make it harder--but not impossible--for grandparents to sue.

Existing ties can make it easier to find an amicable solution. In Prince George's County, Annette Doughty, 58, and Kim Brown, 30, fought for more than a year about Doughty's access to her grandson and Brown's son, Aaron. Brown thought the grandmother was trying to help Aaron's father circumvent a custody agreement that set conditions for his visitation.

Last fall, after Annette Doughty filed suit, a judge sent the family to a mediator. To both women's surprise, they worked out a solution in just one session. Now Doughty gets Aaron one Saturday a month. Brown said one reason she agreed to compromise was that Aaron regularly asked to see his grandmother.

There was no such softening influence in the Sagalow case, and the court fight hardened a family quarrel into a permanent schism.

McKay felt desperate when she went to court in August 1997 to win the right to see Zoe. She loved showering affection and presents on her other three grandchildren, and Michael's siblings praised her impact on their children. But Michael insisted that she could not see Zoe until she started treating his wife with more respect. At one point, he stopped letting his mother listen to Zoe gurgle on the phone because of her demands for a visit.

McKay decided that she had to go to court so that, win or lose, Zoe one day would know that her grandmother had made every effort to see her.

The stakes seemed just as high to the Sagalows. They were afraid that McKay would undermine their relationship with Zoe if she spent time around their daughter. McKay "has publicly denigrated Sarah at family gatherings . . . and could plant disrespectful ideas about about her parents in [Zoe's] mind," Michael Sagalow wrote the court.

They also were worried that McKay, known to be flamboyant and stubborn, would brush off their warnings about Zoe's allergies and expose the child to dangerous situations.

The Sagalows' first response to the lawsuit was to focus on constitutional arguments. They said Maryland's law allowing judges to order grandparent visitation when it is in the child's "best interest" violated their right to raise their daughter as they saw fit.

But when a judge rejected that claim and McKay's attorney called their opposition to visitation "irrational" and "selfish," they felt their backs were against the wall.

During a two-day hearing in Montgomery County Circuit Court, Michael accused his mother of being a congenital liar who had extramarital affairs. Sarah, 47, testified that her mother-in-law had pried into the couple's sex life and had once shoplifted a Batman videotape. McKay denied all those allegations.

Old slights and grudges were painfully reconstructed and relived during the trial, including the story of how McKay had tried to put off the couple's wedding in 1986. She recalled saying to Michael that six months was too short a courtship, while Sarah testified that McKay had told her she "wasn't marriage material." Sarah's mother got on the stand, too, saying that McKay had tried to enlist her aid in stopping the marriage.

Michael described how his mother had asked him for an "exclusive relationship" in which he would keep secrets from his wife.

McKay, for her part, testified that her efforts to please her son's new wife were rebuffed again and again. She had stopped wearing makeup when she visited, because Sarah said she was allergic to it, and still Sarah complained. Sarah had rejected her presents, saying she was allergic to those, too.

The special master who presided at the trial, Steven G. Salant, called it "one of the saddest cases I have ever heard." He ruled against McKay in October 1998. But his report criticized the Sagalows, saying that visiting with her grandmother might hurt Zoe's emotional health because her parents' attitude toward McKay was so hostile.

"While . . . there are tangible benefits to [Zoe] by having visitation," Salant wrote, the Sagalows "have gone beyond fear and distrust to demonization of [McKay]. . . . Granting grandparent visitation under these circumstances would be like throwing a lighted match into a pool of gasoline in which the child stands."

The fight also engulfed the other siblings. At one point during the fight, Michael asked his sister Martyne LoRusso, his brother, Ty, and his brother's wife, Teresa Sagalow, to send affidavits that would criticize McKay for interfering in the upbringing of their children, several family members said. They refused to do that, though they did sign statements saying that Michael and Sarah were good parents.

Michael eventually stopped speaking to Ty, Martyne and his other sister, Jeri Sagalow Spiero.

"It's a tremendous human toll. It ripped the entire family apart," Ty Sagalow said. "Even though both sides said they wanted us to be neutral, at the end of the day we ended up upsetting both of them."

Other families that have been through legal battles over visitation agree that it is hard to bury differences after a faceoff in a courtroom.

"The law getting involved really hurts the possibility of reconciliation," said Sarah Hasty Williams, who, with her husband, fought all the way to Virginia's Supreme Court to prevent his parents from having visits alone with their daughter Leslie. "The court knocked them down and [now] they have to be humble," Williams said of her in-laws. "But it's not of their own choosing, so you never really know if it's real."

McKay and her son, meanwhile, are resigned to permanent silence.

"My son is very mixed up," McKay said. "I know that he is doing what he thinks is best for keeping his marriage intact. . . . I love him to pieces and I wouldn't hurt him for all the world."

For Michael Sagalow, the lesson of his family's story is that grandparent visitation laws do more harm than good, except in the rare cases where a child is in danger.

"This is the most terrible thing in my life," he said. "I have no relationship with my mother. We have no relationship with my siblings. . . . This is what happens when you try to micromanage families."

Staff writer Manuel Perez-Rivas contributed to this report.