"By the dawn of the twentieth century, eugenics had begun taking root in the United States, and there it flowered into darker blooms. American eugenicists wanted to prevent people with bad traits from having children. Some argued for institutionalizing the feebleminded to stop them from having sex. Some called for sterilization. In 1900, an American physician named W. D. McKim went so far as to call for "a gentle painless death." He envisioned the construction of gas chambers to kill "the very weak and the very vicious." It would be pointless to try to improve these people through experience, because, McKim declared, "heredity is the fundamental cause of human wretchedness."