As you say, Sanger referred to black people as inferior. And evidently so did a number of scientists back in the day. Indeed, the linked article mentions several scientists appealing to Darwin's theory to why black people are to be seen as inferior.
Indeed. Thank you for the valuable link, dearest sister in Christ. It shows how science can be abused to come up with "evidence" that supports our presuppositions. A modern example would be anthropogenic global warming. Here evidence has been tampered with, suppressed, or grossly misrepresented in order to fit the conclusion the scientists in question wanted to reach.
Back at the time of the Founding, many if not most Americans did believe that blacks were somehow "inferior." This attitude, of course, pre-dates Darwin's theory by roughly 80 years. But when that theory did emerge, it was used to validate the pre-existing attitude, on the basis of "science," that blacks were "objectively" inferior....
I find it interesting that, at his death, George Washington emancipated all his slaves. When Thomas Jefferson died, he emancipated only five of his slaves — and those he freed are thought to have been his own children by Sally Hemmings. All the rest — including Sally — were not emancipated, but became part of his estate. When Jefferson died, he was massively in debt. I don't know whatever happened to Sally.
The linked article quotes Jefferson: “I advance it, therefore, as a suspicion only, that the blacks…are inferior to the whites in the endowment of body and mind.” It seems to me that "suspicion" has never been confirmed; nor I suspect is it confirmable because it just isn't true.
Which only goes to show that even a brilliant mind like Jefferson could be infected by insupportable presuppositions largely informed by prevailing attitudes in the general culture that are fundamentally false.
The point is, Darwinism if anything seemed to justify these insupportable presuppositions, in time giving "intellectual cover" to the goals of the eugenics movement (Galton, Sanger, et al.).
And the rest, as they say, is history.
Thank you so much for writing, dearest sister in Christ, and for the link to Amanda Thompson's illuminating article, "Scientific Racism: The Justification of Slavery and Segregated Education in America."