Answer:
Reconstruction was the period in American history that began after the Civil War, in which the federal government and the northern states set their sights on the reintegration of the southern states into the Union.
Initially, this period was led by President Lincoln, who was assassinated a month after starting his second term, being replaced by his vice president, Andrew Johnson. Both presidents had in mind a gradual, progressive and delicate reintegration of the southern states, trying that all the actions to be carried out did not imply in any way a return of violence or political unrest in the former Confederate states.
The problem arose when a group of republicans of radical ideology began to oppose these light measures, seeking to guarantee greater rights to African-Americans and to impose greater demands and limitations on southern states. Furthermore, given the Democratic character of President Johnson, this group did not support him in the least. Thus, once Congress was filled with Radical Republicans, tougher measures began to be taken against the South, such as the adoption of three constitutional amendments, the military occupation of the South, or the demand of oaths of loyalty to high percentages of the population of the southern states to re-admit them into the Union.
