In his book One Summer, about America in 1927, Bill Bryson writes:
Remarkably, the Ku Klux Klan was not the most dangerous outpost of bigotry in America in the period. That distinction belonged, extraordinary though it is to state, to a coalition of academics and scientists. Since early in the century, a large number of prominent and learned Americans had been preoccupied, often to the point of obsessiveness, with the belief that the country was filling up with dangerously inferior people and that something urgent must be done about it.
One of the leaders in the fledgling eugenics movement was Madison Grant, a New York lawyer who never practiced law and a naturalist who practiced but was not trained. His preferred race: the Nordics. Bryson explains that by this term Grant meant all northern Europeans except the Irish.
Among those whom Bryson lists as supporters of Grant's views were the great Yale economist Irving Fisher, Harvard neuropathologist E.E. Southard, Harvard's president A. Lawrence Lowell, birth control activist Margaret Sanger, and politician Herbert Hoover.
One of the people who thought in terms of eugenics, unfortunately, was Supreme Court Justice Oliver Wendell Holmes Jr. He wrote the majority opinion in the Court's 8-1 decision that backed forcing Carrie Buck to be sterilized. In that decision Holmes coined the famous line "Three generations of imbeciles is enough." I'm not sure whether he had grandchildren.
Eugenics believer Harry H. Laughlin, whom the House Committee on Immigration and Naturalization appointed as "its expert adviser" and "assigned him the task of determining the comparative degeneracy of various ethnic groups." He pushed for sweeping immigration restrictions. He succeeded. Bryson writes:
Congress could not resist the authority of the committee or Laughlin's horrifying propaganda, and it quickly pushed through the 1921 Gillingham Immigration Restriction Act followed by the 1924 National Origins Act. Together these ended America's open-door immigration policy. By 1927, more people were being deported from Ellis Island than were coming through it.
What happened to Carrie Buck? In October 1927, she was sterilized. So was her sister, who "was told she was being treated for appendicitis."