I think a guerilla war did take place. Freedmen were intimidated, houses and barns burned, race riots, and murders by the KKK: an organization in the late 1860s and 70s, that consisted mostly of Confederate vets. It's a guerilla war that the KKK mostly won, reestablishing white supremacist governments in the former
CS states, and instituting Jim Crow segregation by the end of the century. Jim Crow was propped up by various degrees of illegal violence until the 1960s.