There’s a very illuminating article on the History News Network written by author Edwin Black entitled “The Horrifying American Roots of Nazi Eugenics.”

There’s just a presumption that eugenics proponents in the U.S. were not so extreme as to push killing undesirable people.  From the article:

The eugenicists hoped to neutralize the viability of 10 percent of the population at a sweep, until none were left except themselves.

Eighteen solutions were explored in a Carnegie-supported 1911 “Preliminary Report of the Committee of the Eugenic Section of the American Breeder’s Association to Study and to Report on the Best Practical Means for Cutting Off the Defective Germ-Plasm in the Human Population.” Point eight was euthanasia.

Later in the article:

Eugenic breeders believed American society was not ready to implement an organized lethal solution. But many mental institutions and doctors practiced improvised medical lethality and passive euthanasia on their own. One institution in Lincoln, Illinois fed its incoming patients milk from tubercular cows believing a eugenically strong individual would be immune. Thirty to forty percent annual death rates resulted at Lincoln. Some doctors practiced passive eugenicide one newborn infant at a time. Others doctors at mental institutions engaged in lethal neglect.

I’d like to clarify that the Committee report mentioned above didn’t support euthanasia as an option, although it did support forced sterilization.

Here’s an interesting except from the Committee report:

In a letter dated January 14, 1913, to this committee, Theodore Roosevelt says:

As you say, it is obvious that if in the future racial qualities are to be improved, the improving must be wrought mainly by favoring the fecundity of the worthy type and frowning on the fecundity of the unworthy types.  At present we do just the reverse.  There is no check to fecundity of those who are subnormal, both intellectually and morally, while the provident and thrifty tend to develop a cold selfishness, which makes them refuse to breed at all.

I highly recommend reading this chilling article and the report.