What is the main conflict in Mudbound by Hillary Jordan?

In this novel, two families' lives are irrevocably changed by the events of one night. Laura thought she would never get married, but soon finds herself a wife and mother living on a farm in the Mississippi Delta, dealing with the mud, a cantankerous father-in-law, and a drunken brother-in-law haunted by what he has seen and done in the war. At the same time, strong-willed Florence finds herself fighting a battle on the home front to protect her family from the racism that threatens to poison all she holds dear.