One of the first books that rekindled my interest in Science Fiction as an adult was "The Man in the High Tower" by Philip K. Dick. This classic story involves a parallel world in which the allies lost World War II.
"Bring the Jubilee" was written at the end of World War II, and deals instead with a parallel world in which the South won the American Civil War (which is instead referred to as "The War of Southron Independence"). "Bring the Jubilee" does not get bogged down in the same kind of metaphysics as "The Man in the High Tower" (there is a navel-gazing point in that work in which the characters realize theirs is not the world that was meant to be). Instead, as with "Earth Abides", "Bring the Jubilee" is a work which is earnest and direct in a way that later books tend not to be. Instead of philosophy, we get details about daily life in a world in which indenture is common, and in which the remaining 26 United States are a part of the third world while the Confederacy is a center of learning and commerce.
I plan to run this one by my friends who are more up on their Civil War history and hopefully start a few good conversations. Until then, I'll hold my tongue to avoid giving anything away.