Yesterday was Nellie Gray's day. There she was, a gauzy red scarf tied around her graying, carefully arranged hair, right behind the line of fresh-faced teen-agers carrying the right-to-life banner at the head of the march.

For the last five years, since the U.S. Supreme Court legalized abortion, Nellie Gray has headed up the organizing of the March for Life, held each of those years on Jan. 22. Yesterday, U.S. Capitol police estimated that 60,000 people showed up to carry red roses to their senators and representatives and lobby them to outlaw abortion.

Nellie Gray is 54, unmarried, childless, a career woman who left a government job she loved, to work for a cause she thinks is crucial. She believes that a human being exists from the moment of conception. She is against giving birth control advice to teen-agers. She is opposed to aborting pregnancies conceived by victims of rape.

She signs her letters "Sincerely in Life," before appending her distinctive signature underscored with a swooping line with two tiny slashes through it.

"We begin a new wave of pro-life action!" she opens her latest Dear Marchers for Life letter. "Where abortionists have sown hostility, we will sow peace and love! ... For some time, the shock of the abortionists' callousness was met by pro-lifers in the spirit of trying to educate the misguided evil-doers about the humanity of the pre-born child... After six years... it is clear that abortionists -- driven by their megalomania -- will not be persuaded by logic, facts, moral arguments -- they understand only the force of being told clearly that their hideous activities will not be tolerated in our precious society."

But yesterday was also Karen Mulhauser's day. She is the 36-year-old executive director of the National Abortion Rights Action League (N.A.R.A.L.), and along with Gloria Steinem, the National Organization for Women, and other groups, she celebrated the anniversary of the Supreme Court's decision with a press conference and renewed dedication "to protect the status quo."

"They want the Constitution to give a fertilized egg the same protection under the law that born individuals have. ALL abortions would be considered premeditated murder," Mulhauser said at the press conference. "Every year more women in the U.S. have natural abortions [miscarriages] than have induced abortions. All abortions, natural and induced, would be subject to litigation and prosecution [under the proposed "pro-life" amendment]. In addition, the more effective birth control methods, such as IUDs and some birth control pills, would be outlawed...."

The March for Lifers carry red roses "as a beautiful living reminder of the pre-born child." Yesterday, the groups that call themselves "pro-choice" said they will also be sending legislators "one dead Rose -- the story of Rosie, a real woman who was once alive, and who died at the age of 27" after having an illegal abortion.

Gloria Steinem called this War of the Roses "a kind of intimate Vietnam for women." Certainly some of the superficial aspects of the battle resemble that of the one over the war -- the marches, the cries of "baby-killer," the lobbying and attempts to elect or defeat legislators, the bitter arguments between friends and family.

Nelie Gray and Karen Mulhauser are two of the generals in this war -- on opposing sides, fighting for the hearts and minds of the people and those who govern them. Nobody Is Pro-Abortion

Karen Mulhauser lives, ironically, a few blocks from Nellie Gray's Capitol Hill town house. With her son, Chris, now 8, and her husband, Frederick, who works for HEW, she moved to Washington five years ago to work as N.A.R.A.L.'s lobbyist.

She has not had an abortion; her son was born in the seventh month of pregnancy after several miscarriages, one of them at six months. One of her best friends in high school, one of her close friends at Antioch College, had abortions, as did dozens of women she counseled at a pregnancy counseling service in Boston where she worked before abortion was legal. She does not take abortion lightly. "Nobody thinks that abortion is a pleasure," she said. "Nobody is pro-abortion.

"Just knowing the desperation, the anguish, the terrible dilemma of all those women I counseled in Boston, that experience is what I think back to most of all in my political work."

She says she used to be "the girl at the back of the class who never raised her hand." Now she handles press conferences, interviews and debates with aplomb, runs a lobbying group whose membership has grown in the last 18 months from 8,500 to 60,000.

Mulhauser grew up in the small town of Groton, Conn., home of a famous prep school and a town where her parents joked they were half of the registered Democrats. Her mother, who had a PhD in botany, got married at 35 to a man 10 years younger and then raised five children. They had three weddings, one for her Jewish father's family, one for her Protestant mother's family and one for themselves. Her father, who has a degree in genetics, is a consultant in "mariculture," the study of harvesting food from the ocean. Two of her brothers are mathematicians, another is a carpenter and her sister "is a warm loving person who has turned to Jesus" and lives with her husband and children in a community in Montana.

"I have quite an interesting family," she said.

After getting a degree in biology and biochemistry at Antioch, trying one semester of medical school and 18 months as a biochemistry research associate at the Albert Einstein Medical College, she decided "I'd rather work with people than test tubes," and took a job teaching high school.

Now, she admits, "I'm a workaholic. Fortunately, my husband is too. But we have one rule -- we don't open our briefcases at home until Chris is in bed."

Her office is decorated with family pictures, child's drawings and several versions of the pregnant man poster.

"Pro-choice is a hard constituency to organize," she said, "I wish the over one million women a year who have abortions would talk about it. Human sexuality is hard to talk about." Something Sick and Evil

Nellie Gray grew up in a small town in Texas during the Depression, the daughter of an auto mechanic and a housewife. "It was still a time of love of family, love of country, love of community and love of one another," she said.

After high school, she worked for a year as a secretary before finding the money to start attending Texas State College for Women. After the Japanese attacked Pearl Harbor, "as soon as I was old enough, I joined the Army." She was in the Army from 1944 to 1946.

She first heard of abortion when she read the novel "The Cardinal." She described a scene in the book where a "woman is about to give birth and the birth canal is too small, so the doctors reach in and crush the baby's head. The whole notion of that grabbed in my gut."

None of her friends was ever pregnant out of wedlock, and abortion was not an active concern of hers until 1970. "It wasn't talked about. It was known to be something not done in civilized society, something sick, and evil."

Although baptized as a Roman Catholic, Gray said she received no religious training until she was 18. "In was aware I wanted something but I didn't know what it was," she said, "I embraced the church very enthusiastically. It has been a very strong influence in my life."

She left Texas and came to Washington, working in economic research with the State Department and later those," said Gray, a Democrat. "That's how I got all my jobs." going to Georgetown University Law School at night. She later worked with manpower training programs in the Department of Labor's legislative division.

"I feel very supportive of manpower training, and social programs such as

She left her job in 1973 to work as the president of March for Life, Inc., living on her retirement benefits (which were halved because she retired early.) Now her life is almost totally occupied with the "movement;" March for Life has offices in her basement, and the mimeograph machine near her desk is always ready to crank out more press releases in red ink. To Be a Victim

Four months ago, during the days of debate in Congress on the Hyde amendment that eliminated federal funding for abortions for poor women in cases of rape or incest, Karen Mulhauser was at home after a long day of lobbying. Her husband was out of town. At about 1 a.m., she said, two armed men broke into their house, ripped off their stereo, and raped her repeatedly. She has decided to talk about it.

"There are reasons why people get involved (in a cause). And reasons that reconfirm your commitment... I was convinced that I was not going to survive. They had a gun at my head. I found myself getting angry not only at the rapists, but at these men in Congress who will not allow funding for rape victims. Suppose I had gotten pregnant? There is no way I would have continued that pregnancy. I now know what it is like to be a victim..."

Two weeks ago, she said, the men who raped her were sentenced to long prison terms. Driven to Extremes

Nellie Gray says that very few women get pregnant when they are raped. But for those few who do, she said, "can you overcome this aggravated assault by killing a baby?" The United States Supreme Court has said that in a case of aggravated rape, capital punishment is cruel and unusual punishment. Then why would you want to visit that punishment on a pre-born child?"

She thinks the "baby-killing movement" has "injected hostility into America." Before abortion became an issue, she said, "the normal relationship for a mother and her child was loving and caring. Suddenly they're promoting something devastating about pregnancy... and people are making money from that hostility in abortion clinics across the country."

Yesterday Eleanor Smeal, who heads the National Organization for Women, said that NOW was inviting 20 pro-life groups, including March for Life, and 20 pro-choice groups, including N.A.R.A.L., to meet together to discuss common goals.

"Both groups are being driven to extremes on this issue," she said, "We believe the confrontation has become destructive. We don't think either side will change its position on abortion, but we have one common goal -- to reduce the need for abortion. It's time to look for realistic solutions."

Karen Mulhauser immediately accepted the invitation. Nellie Gray said, "I do not sit down and negotiate with baby killers." Not Much Time

Mulhauser regrets she no longer has much time to sew and bake. "I used to make all my clothes," she said somewhat wistfully. Her spare time now, she spends with her husband and son, taking weekend trips or -- lately -- reading "The Lord of The Rings" aloud.

Nellie Gray used to play bridge, but she doesn't have much time for that anymore.The phone rings in her house at all hours of the night. She said she has learned to recognize the voice of an unmarried, pregnant woman after the first sentence or two.

Both Mulhauser and Gray see long years stretching out in front of them filled with the turmoil of the abortion fight. "In the future, people will probably look back at this era and say 'what on earth was going on when they were thinking about taking away a voluntary service?'" Mulhauser says.

"We will never compromise," says Gray.