Here is a study that gives a completely encyclopedic coverage of the context, data, and knowledge of the time. [1] If you're at all interested in this topic, I'd strongly encourage checking it out. It is the most extensively informative paper, on any topic, that I have ever seen, by far. I have no idea how many years the author spent collecting the data he presents there but it was clearly a labor of love.
For some relevant points: in Georgia, they carried out widescale syphilis testing, on the scale of hundreds of thousands in 1945. Counties adjacent to Tuskegee reached 89% test coverage, with the outcome being an infection rate of 30% in black individuals and 3% in white individuals. Of course people wouldn't have known the exact numbers back when the Tuskegee study started in 1932, but with such ridiculously high rates of infection, they'd have had a generally accurate idea. It's also accurate that the majority of those who were infected had not proactively sought out medical treatment. That knowledge is part of what led Georgia to mandate the blood tests and pair it alongside recommendations of treatment for those infected. How do you think you would have framed these data at the time with a wide open Overton Window, no notions of political correctness, and so on?
To be clear, as always, I am not defending the Tuskegee experiment, the people who did it, their views, or anything of the sort. They did awful things, obviously. But what I am trying to show is that if we were in their shoes, in the same situation, in the same context, it would have been all too easy to fall into the exact same trappings. It's only by really understanding the past that we might ever try to hope to avoid repeating it. When we simply demonize the past, the only lesson to be learned is don't be a demon. And certainly none of us think ourselves demons, so surely such things could never happen again. But with that mindset, they most assuredly will!
[1] - https://jamanetwork.com/journals/jamainternalmedicine/fullar...