In 1861, the Conflict between the North and the South caused by the expansion of slavery intensified. The American Civil War broke out. After years of bloody fighting, the North gradually gained the upper hand on the battlefield and began to deal with rebuilding the south. Reconstruction is divided into two phases: Presidential Reconstruction and Congress Reconstruction. Why did the federal government and the reconstruction government in the southern states fail to effectively suppress the violent white resistance? How could there be such a dramatic change in northern attitudes towards the Reconstruction? Was the failure to congress reconstruction an accident, or was it an inevitable result? In my opinion, the failure of congressional reconstruction is inevitable and I want to find this out.