I stated up front that it's the opposite of our current narrative, so telling me this doesn't actually add anything at all to the conversation.
The book was very well documented. At the time, I had no idea it said the opposite of the usual framing or might have made more effort to remember the title and author.
The book suggested the Federal policy initially failed in its goal because racist whites in the South simply fired blacks rather than "pay them a white man's wage." The start of WW2 helped it eventually succeed, but there was also a fairly widespread exodus of blacks from the rural South to urban centers elsewhere in the US as a personal means to solve such problems on an individual basis.
I was homeless for several years. During that time, I did piece work. Initially, it was common for my hourly earnings to be well below minimum wage, like as little as $1.25 an hour. Over time, this changed.
So I am actually a proponent of the idea that we need to make it possible for people to work for less than minimum wage so they have the ability to better than themselves. I don't think it's a good idea to allow wage work per se to be that low because it easily becomes an inescapable personal hell. But we do need to design work opportunities that can pay less than minimum wage if it takes you a long time to complete it, but also has the ability to become a more middle class income if you get good at and thus get faster or otherwise qualify for similar work that nonetheless pays better.