Neil Kingsblood is a banker in a small city in Minnesota. He lives a Dick and Jane life in the suburbs with his wife, Vestal, and his 5-year old daughter, Elizabeth, known as Biddy. Neil's father gets him interested in some old family lore about how they might be related to royalty and convinces Neil that he should do some geneological research. What Neil learns is that he had a great, great, great grandfather who was a negro and who married an Chippewa Indian. Thus, Neil, had a drop of "tainted" negro blood, making him "tainted" as well.
What to do? Should he tell Vestal? His father? His boss and co-workers? It doesn't help that Neil lives in a horrifically racist society. More racist by ignorance than direct intention. So, first of all, he decides to befriend some negroes and try to learn a bit more about them. It turns out, that negroes are mostly normal people, just like the rest of us. This revelation doesn't help Neil all that much. He still needs to know coping mechanisms for dealing with the racism of others. He still worries about his marriage and his "tainted" child. After all, if no one knows about his tainted blood, what's the harm?
But, he can't help himself. He admits to one person and another about his taint. Naturally, no individual person is prejudiced, but, you know, "other" people will begin to complain, and that will be bad for business, or lower property values, or whatever.
It's weird to read this stuff thinking that we've come a long way in the last 70 years, then realize that we just elected a President who is totally ignorant about the basics of government, ethics, the Constitution, Christianity, you name it. But, he knows how to play on people's race fears. For the first time since 1948, it became "safe" for the Klu Klux Klan to publicly endorse a Presidential Candidate. Yeah, we're so over racism in the U.S. ["Oh, but it's not me, but we do have to worry about our business model, and ...."]