After reading Puddn'head wilson and Iola Leroy, I can't help but wonder if novels that dealt with the same issues, that being blacks being raised as whites only to discover they are actually black... was a popular one in those years.
I suppose one could argue that novels with slightly taboo subjects would be popular, but it could be a way to educate people. There was no TV, no internet in those times, so I am sure escape reading was very much the vogue in those days, especially with books being so widespread what with the printing press. Mass printing would have been an easy thing to accomplish.
Because of this, writing books that show that one learned how to live by being around the culture, regardless of race, people are just the same as the person next to you. I am sure women and many african americans read these novels, perhaps helping to give them inspiration to pursue equal rights in America in the end.