What was the nature of the disagreement about the terms under which former confederate states might rejoin the union after the civil war

The two following social problems that the nation faced at the end of the Civil War was c) the existence of four million freed slaves without money, education, or job skills and d) figuring out how to bring the Southern states back into the Union. There was also resistance from White Southerners who did not want to stop slavery or join the Union, which made the process of solving these two social problems harder.