Unmentionables (Unmentionables #1)
David Greene

Unmentionables is the story of two pairs of lovers in the American Civil War south. One couple is straight, white and wealthy. The other couple is gay, black and enslaved.
Field hand Jimmy meets Cato, a house servant from a nearby plantation. Over time, Jimmy's fascination with Cato grows into romantic love. This is the first book ever written about enslaved gay men.