I am trying to know more about the personal lives of the 8 Justices engaged in Plessy v. Ferguson (1896), and whether personal opinions (e.g. racism) might have affected their decision.
I did discover the following evidence of racism for 2 of the Justices:
Edward Douglass White, Jr. had joined two white supremacy organisations;
Justice John Marshall Harlan I had revealed his opposition to the Chinese directly in his dissent.
But what of the other 6?
I'm not a historian, but the question may be somewhat problematic. "Evidence of racism" by today's standards probably doesn't mean much by the standards of 1896.
There's great discussion about "presentism" in this post
Not to shut down further discussion, of course. I hope a historian can shed more light on the personal character of these judges.