The older child, home from college, was disappointed to learn that birth control pioneer Margaret Sanger was a prominent advocate of eugenics. But she was. So were many others.

The eugenics movement drew from modern science of the time and older conceptions of national purity, many of them originating in German romanticism. The history of eugenics is a devious one, connecting many individuals with little else in common.

In a 1932 speech titled (euphoniously) “My Way to Peace,” Sanger advised that the establishment of a Population Congress would “apply a stern and rigid policy of sterilization, and segregation” to the 15 million or so “mental and moral degenerates” threatening our great nation with procreation.

The group would include not only “morons, mental defectives, (and) epileptics” but also “illiterates, paupers, unemployables, criminals, prostitutes, (and) dope-fiends.”

On immigration, Sanger advised “opening the gates of the USA to those countries whose inhabitants have the inherent traits and national characteristics desirable, eliminating entirely those countries whose subjects have already been difficult to assimilate.”

She didn’t exactly say “s---hole countries,” but I don’t have to tell you who that sounds like. The connection between immigration and eugenics was organic: Both were concerned with protecting and improving the national “stock” or “race.”

Sanger was a leading feminist, as were other eugenicists, including Charlotte Perkins Gilman and (briefly) Helen Keller. Sanger was a pacifist: All this would lead to “WORLD PEACE.” She was a progressive: Science, not tradition or religion, would lead the way forward. Her thinking can be traced to Francis Galton, the founder of eugenics and cousin of Charles Darwin. “Survival of the fittest,” a term coined by “social Darwinist” and scientific racist Herbert Spencer, could be sped up, for the good of everyone — everyone who was thought to matter, anyway — with a scientific program of forced sterilization.

But the fit were going to survive in any event. In his 1871 “Descent of Man,” Galton predicted that “at some future period, not very distant as measured by centuries, the civilized races will almost certainly exterminate, and replace, the savage races throughout the world.”

Foreseeing a similar fate for higher apes such as gorillas, Galton concluded that “the break between man and his nearest allies (apes) will then be wider, for it will intervene between man in a more civilized state, as we may hope, even than the Caucasian, and some ape as low as a baboon, instead of, as now, between the negro or Australian (aboriginal tribes) and the gorilla.”

The actual author of “The Descent of Man” wasn’t Galton but Charles Darwin himself. This wasn’t the fringe thinking of “scientific racists” (as they are often ahistorically classified). Mainstream science at the time seriously debated the question of whether the “barbaric” or “savage races,” as they were inevitably called, would survive competition with Caucasian (or “Anglo-Saxon”) stocks, which were thought (by Caucasians) to pose a special threat to other races.

The question figured prominently in America’s Reconstruction era after the Civil War. Addressing the debate in his third autobiography, the great African-American leader Frederick Douglass noted that the U.S. census of 1880 had shown an increase in the black population of the U.S. This disproved the idea, Douglass wrote, “that, like the Indian, we shall perish in the blaze of Caucasian civilization.”

But if Douglass strikes a dissonant note in predicting the extinction of “the Indian,” he had spoken out forcefully against President Abraham Lincoln’s 1862 plan to colonize freed slaves outside the U.S. Although it’s possible that Lincoln was merely repeating for popular consumption what had long been an abolitionist talking point, the balance of evidence suggests, according to the historian Eric Foner, that “Lincoln’s support of a policy that might be called the ethnic cleansing of America was no transitory fancy.”

Ethnic cleansing on an industrial scale was central to history’s most notorious eugenicist, Adolf Hitler, whose early sterilization program borrowed from experts in the U.S. The Holocaust, however, rendered the movement irredeemably noxious. Even North Carolina disbanded its Eugenics Board ... in 1974.

Fortunately, Hitler’s psychotic fantasy of a racially pure German nation remained unrealized because of the heroic efforts of such men as Winston Churchill. Also a eugenicist, Churchill wrote in a 1910 letter that “the unnatural and increasingly rapid growth of the Feeble-Minded and Insane classes, coupled as it is with a steady restriction among all the thrifty, energetic and superior stocks, constitutes a national and race danger which it is impossible to exaggerate.”

A year later, he advocated in the House of Commons for the creation of compulsory labor camps for “mental defectives.”

In an age that continues to debate genetic design (including “designer babies”), women’s control over their bodies, the state’s control over women’s bodies, selective abortion, the genetic basis of race, the genetic basis of everything else, the relationship between science and morality, the rise of racialized nationalism and the question of who belongs in nations, the issues surrounding eugenics remain unsettled.

If you believe otherwise, you’re ignoring history.

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