On Saturday, while thousands of people gathered at rallies across the country to protest the potential overturning of Roe v. Wade, a gunman entered a supermarket in Buffalo with what authorities say was the intent to kill Black people. Although it was coincidence that these two events happened on the same day, understanding them together reveals the shared roots of racist violence and antiabortion policies. Both are part of a long history of American anxiety about fertility and the reproduction of a native-born “White race.”

Authorities say the Buffalo suspect left an online screed centered on the “great replacement,” a debunked idea that claims there is a plot to replace the White population with immigrants and African Americans. Republicans have made the theory mainstream recently, but it also has a longer history connected to racist and eugenic concerns about the supposed demographic decline of the native-born White population. These same concerns helped make abortion illegal in 19th-century America, and at least some right-wing activists, like Matt Schlapp, the influential head of the Conservative Political Action Conference (CPAC), see a tie between the two issues today.

During the 18th- and early-19th centuries, stopping a pregnancy before quickening — when the pregnant woman could feel fetal movement — was not considered an “abortion” at all in our modern sense of the term. Women were aware of methods to restore menstruation before quickening and these practices were not criminalized, although there was some regulation of abortifacients if they were seen as dangerous to the pregnant woman’s life.

This began to change after 1857, when the American Medical Association (AMA), a new organization at the time, launched a campaign to make abortion illegal at every stage of pregnancy. The campaign stemmed from physicians’ desire to gain professional authority, to control and regulate the practice of medicine and to restrict their competitors, including midwives.

The AMA’s campaign against abortion gained steam from anxieties about immigrants in the late-1850s, and after the Civil War, about the free Black population. Supporters of criminalizing abortion claimed that the birthrate was declining among native-born Whites, even while immigrants, many from Southern and Eastern Europe, were having large families.

The leader of the medical campaign against abortion, the physician Horatio Storer, lamented that this pattern of fertility could portend a disaster for the spread of U.S. power across the continent. Imagining a southern and western United States populated by African Americans, alongside immigrant Mexicans, Chinese and European Catholics, he asked whether those regions would be “filled by our own children or by those of aliens?” To Storer, “the future destiny of the nation” depended upon the “loins” of White women.