Twenty years ago, Dorothy Roberts, the George A. Weiss University Professor of Law and Sociology at Penn Law School and the School of Arts & Sciences, released her formative book, “Killing the Black Body: Race, Reproduction, and the Meaning of Liberty,” which laid bare the systematic assault on the bodies of black women in the United States.

Roberts, also the Raymond Pace and Sadie Tanner Mossell Alexander Professor of Civil Rights, says she was driven to write the book after reading news articles in the late 1980s about black women who were arrested and jailed for using drugs while pregnant. Roberts saw the prosecutions as punishing black women for having babies, which led her to research the history of punitive policies directed toward African-American women, and write about the regulation of their childbearing.

“The other thing that motivated me was that I was, at the same time, studying feminist theory and jurisprudence, and I was struck by the way in which most scholars neglected to address these issues that were especially relevant to black women,” she says.

“Killing the Black Body,” published in 1997, chronicles the war against black reproduction, from slavery to present day. The chattel property of their masters, enslaved black women were valuable for their reproductive labor and had no legal right to control it. Their owners had the legal power to exert complete control over their bodies, deciding when they would have children, and with whom. The more children an enslaved woman produced—to be owned and sold at her master’s discretion—the more valuable she was, which Roberts says “led to a regime of practices, and laws, and ways of thinking about black women’s bodies that permitted coercion of their reproduction.”

When slavery ended and the wombs of black women could no longer be seized for financial gain, policies were put in place to contain, control, and punish black reproduction, which was deemed a danger to society. Roberts says these oppressive policies continued through the eugenics era, and into the 1960s and ’70s, and were being implemented at the time she was conducting her research.

For the book’s 20th anniversary, “Killing the Black Body” has been reissued, with a new preface from Roberts, who reflects on its publication and findings two decades later. She has continued her work on contesting anti-black reproduction policies, and says many of the programs have intensified.

Roberts says the original motivation for her research—the prosecutions of black women who use drugs during pregnancy—continues to this day, with states passing fetal protection laws to make it easier to prosecute women for their conduct during pregnancy.

Furthermore, a year before the book was published, President Bill Clinton signed the Personal Responsibility and Work Opportunity Reconciliation Act, a major restructuring of the welfare system that Roberts says allowed states to enact policies designed to deter women on welfare from having children, and regulate the reproductive and sexual decisions of women receiving benefits.

Roberts argues in “Killing the Black Body” that conditions placed on welfare recipients are a form of regulating black women’s bodies, and were promoted by stereotypical images of black “welfare queens who supposedly had children just to get a welfare check.” The conditions were being proposed when she was finishing the book; now, she says they have been implemented in many states.

Restrictions on the right to abortion have also escalated since the book was published. Roberts says states have passed hundreds of laws in the last 20 years, which disproportionately affect black women, designed to keep women from accessing abortion services.

“Under the current administration, there are proposals to restrict access to family planning and other needed health care for women even more,” she says.

At the conclusion of “Killing the Black Body,” Roberts proposed a new way of theorizing about reproductive freedom focused on social justice. She says a positive development over the past two decades has been the burgeoning of a reproductive justice movement led by women of color that has contested not only harmful reproductive policies, but also “the inadequate framework of choice as the basis for advocating for social change.”

“Reproductive justice is grounded in the struggle for social justice that goes beyond an approach that focuses on individual women’s choices,” she says. “That has proven to be a much more powerful and inclusive way of thinking about and advocating for reproductive freedom.”