After the Civil War (1861 - 1865), Congress felt that the South should pay a heavy price due to their attempt of secession (attempt to leave the Union) and due to the destruction left by the war and its casualties.
The Reconstruction period, the division of southern states into 5 military districts (each administered by a Union general), the abolition of slavery in the US and the readmission process to the Union were just some of the negative consequences faced by the South at the end of the Civil War.