Here's an even better factoid: Hitler's concept of eugenics came from the United States. It's little known that at the time the United States was forcing sterilization on the mentally ill so as to prevent them from "weakening the gene pool".

The point is illustrated here, here and here.

By one account:
One approach of the eugenicists was sterilization. The principle was that sterilizing large numbers of "defective" people could prevent the perpetuation of targeted defects and genetic diseases. The state eugenics laws were tested in the courts. The Supreme Court ruled in favor of the eugenicists in Buck vs. Bell (1927). Justice Oliver Wendell Holmes speaking for the Court, wrote, "three generations of imbeciles are enough". State governments under the authority of these laws forcibly sterilized thousands of Americans. Most of those sterilized were poor children being cared for in various state institutions. Many did not known what was being done to them ast the time. The operations were caried out foricibly if the individuals objected. We do not have an estimate yet of the actual number of people sterilized. As these operations were sometimes conducted covertly, an accurate assessment is probably not possible. An estimated 60,000 to 100,000 people are believed to have been sterilized, but in fact there are no precise records. The mentally ill and retarded were the most frequent victims of this program. There were also, however, children and youths sterilized. These included unwed mothers and boys in reformatories and orphanages, especially if they were judged to be retarded. The extent of the sterilizations varied widely from state to state, but was most pronounced in states that were largely Protestant because of the opposition of the Catholic Church. There were also large numbers of sterilizations conducted on blacks in the South by the largely white medical establishment. These were known as Mississippi appendectomies.