Once again, the unwed mother has become a symbol of what is wrong with society.

Secretary of Health and Human Services Louis W. Sullivan calls out-of-wedlock births a reflection of the "ugly underbelly of American culture" -- the environment of poverty, illness and violence that is decimating inner-city America. He points to the fact that 62 percent of black children are born into fatherless households.

For centuries, the plight of the single woman who gets pregnant has been the stuff of novelists and the staple of preachers. Today, the escalation of births to unmarried women is one of the most troubling health statistics, because of its correlation with lifelong poverty. One million babies in the U.S. are now born to single women every year -- one quarter of all births. Since 1980, there has been a 50 percent increase in births to unmarried mothers.

Despite publicity about single professional superwomen who elect to have children without husbands, most unmarried mothers are poor and have little education. They are disproportionately black. But as Joel Kleinman, director of analysis at the National Center for Health Statistics, notes: "Class is the real issue. Among college-educated black mothers, 90 percent of births are to married women."

Overall, being born into a fatherless household is associated with higher infant mortality rates and lower social and economic status.

In the face of these grim statistics, it's tempting to call in the medical moralists and resurrect some virtuous bygone era when nice girls didn't have sex or get pregnant outside the boundaries of marriage. But a closer look at the past quickly shatters that myth.

"A Midwife's Tale -- the Life of Martha Ballard, Based on Her Diary, 1785-1812" provides a fascinating chronicle of the most intimate social patterns of a rural community in Maine two centuries ago. What is striking in Martha Ballard's diary is the high rate of pregnancies among unmarried women -- and the acceptance of sex before marriage and pregnancy out of wedlock.

Of 106 babies born to first-time mothers between 1785 and 1797, nearly 40 percent were conceived by single women.

For the community, unmarried pregnancy was less a moral issue than a practical one of arranging support for the child. Most of these women married the father before the child was born, but for those who remained single, the process of establishing paternity was straightforward: The woman told the midwife the name of the father during delivery. The courts, on the assumption that a woman would not lie at such a time, then held the man responsible for the economic support of the child.

"There is no evidence that in rural communities women who bore children out of wedlock were either ruined or abandoned," writes the author, Laurel Thatcher Ulrich, a history professor at the University of New Hampshire. A fundamental tenet of the community was that "fathers as well as mothers were responsible for children out of wedlock."

Two hundred years later, health officials are only beginning to bring unwed fathers into the equation of parenting. Most government programs such as Medicaid and Aid to Families with Dependent Children do not involve the father but focus solely on the mother and child, or children.

Meanwhile, the social status of the unmarried pregnant woman has plummeted. In Martha Ballard's Maine, all the leading families had unwed pregnancies. Ballard, whose husband was a selectman, the New England equivalent of a city council member, delivered one baby born to an unwed mother who confessed that the father was Ballard's own son. "Sally declared that my son Jonathan was the father of her child," she recorded in her diary.

Another change is society's attitude toward marriage. For the pregnant single woman in 1791, marriage to the father was clearly seen as a solution. In 1991, it is not.

"There's much less stigma associated with having a child outside of marriage," says Kristin Moore of Child Trends, a private Washington-based research organization. "Why form a marriage solely to legitimize a birth if the marriage is likely to fall apart?"

Twenty years ago, nearly half of the newborns conceived out of wedlock were legitimized by marriage before birth; in the 1980s, that figure dropped to 25 percent.

Besides, not getting married makes good health sense for pregnant teenagers. Statistics show that under age 18, mothers -- and their children -- do better if they do not marry the father but live with their parents and stay in school. In this way, they are like the unwed mothers of 200 years ago who kept their babies, stayed with their parents and often married someone other than the child's father several years later.

But the main message from Martha Ballard's diary to modern health officials is not about the morals of marriage but the realities of sex. "In courtship, sexual activity was connected with a comprehensive transition to adulthood, to good citizenship and economic productivity," writes Ulrich. It was a social and legal system that "required an acceptance of female sexuality and an acknowledgment of fleshly sin." At the same time, continues Ulrich, "it did hold men responsible for their behavior."

That's not a bad framework for building an effective public health policy to deal with unmarried parents and their children.