This is one of those hidden pieces of American history that is rarely discussed. Eugenics is an outcropping of humanism.
Eugenics in the USA is the direct result of Industrial Capitalism. By the turn of the century in 1900 the major newspapers were all owned or controlled by those who had control over industry. They realized that they could not afford to pay one man enough to have a large family so they set about to convincing the common man to have smaller families. They began promoting easy divorce, contraception and abortion, all things that the Rich were able to obtain were offered to the average Joe and Jane.
Knee-jerk accusations of Socialism should be checked at the door. We have Socialism and Capitalism coexisting in great harmony; something else that Chesterton predicted. I am no Socialist, nor a capitalist. I'm a "wage slave" like most folks today. The answers reside in some exercising of some intellectual muscles that are generally subordinated to imagination. It should be the other way around.
My debt to FJ Sheed should be acknowledged.