What was the process of bringing the confederate states back into union?

The process of bringing the Confederate States back into the Union was called Reconstruction.

Explanation:

Reconstruction refers to the time after the Civil War. The term indicates both that large parts of the country had to be rebuilt, and that the Southern states had to be transformed from slave economies to states where the former slaves were now free citizens with civil rights. So-called radical Republicans wanted to enact laws, institutions and governing powers that guaranteed such rights for all Americans, while Presidents Abraham Lincoln and Andrew Johnson leaned toward a more moderate line to try to stabilize the Union as quickly as possible.  

During this time, the Constitution made three changes, known as Reconstruction Amendments. These abolished slavery and forced labor, gave equal protection under law, and prohibited discrimination on grounds of race, color, or past condition of slavery. Congress also passed the first Civil Rights Act, the Civil Rights Act of 1875, which banned discrimination in public transportation, public places and in juries. But after about a decade of rapid change, conservative forces struck back many of them, and the reconstruction period is said to continue even in 1877, when the last federal troops were withdrawn from the Southern states.

true

coz they had the rank system in society according to the economic power of the people