The purpose of Reconstruction was to provide the terms for the readmission of the rebellious Southern states into the Union. The Reconstruction period occurred between 1865 and 1877.
The primary condition set by President Abraham Lincoln was for the rebellious states to swear an oath of allegiance to the Union. A group of anti-slavery Republican Congressmen called the Radicals denounced Lincoln's lack of provisions for black civil rights, along with economic and social reforms. With the assassination of Lincoln in 1865, Congress was able to wrench control of the Reconstruction policies with an outstanding victory of more than two-thirds of Congressional seats.