What is the name for the period after the Civil War when the states were brought back into the Union?
The southern states had been decimated by the Civil War. The problem of how to transition people who had previously been slaves into a members of a free society was part of reconstruction.
Sadly despite early success the Freedom's Bureau and Reconstruction failed. Jim Crow laws, and share cropping left many former slaves and their children in worst economic conditions .Slave culture was replaced with a caste system that left the African American people in a position of being subservient to white people.
The period of Reconstruction ended with the Southern States being readmitted to the Union. But failed to truly free the previous slaves.