The first issue that the nation faced after the Civil War was determining how to bring the seceded states back into the Union. The question, which had emerged even during the war, at once became a matter of contention between the president and the Congress. Lincoln's wartime plan for Reconstruction of the southern states was to readmit them on liberal and easy terms, but the conditions that Congress wished to impose were much more severe. Andrew Johnson, who became president on April 15, 1865, after the assassination of Lincoln, initially espoused views on Reconstruction similar to those that Lincoln had voiced during the war. However, his attempt to put them into effect without consulting Congress, as well as his tolerance of southern violence against the freed slaves, brought about a series of bitter disputes between the executive and legislative branches of the national government. The quarrel was won by Congress, which overrode the president's veto and passed its own plan, the Reconstruction Acts of 1867. By this plan, most of the South was divided into five military districts, each supervised by a Union major general in command of a detachment of troops. Suffrage was granted to the black male population; and by the third section of the 14th Amendment (adopted 1868) to the Constitution, the former political leaders of the South were denied participation in the various state governments set up by the Reconstruction Acts.
The resulting Reconstruction governments provoked great resentment in the South. Most white southerners claimed that the blacks who won office during Reconstruction were incapable of running the government. Southerners also contended that the white northerners who had moved to the South and earned positions in the Reconstruction governments sought only to plunder southern treasuries (see Carpetbaggers). These charges, however, were generally untrue. Although economic opportunism and official corruption were certainly facts of life in the South, they were no more prevalent than elsewhere in the nation. Southerners simply were unwilling to accept any form of government in which blacks and northerners played a significant role. They attempted to disrupt the Reconstruction governments with outbreaks of violence and through intimidation, orchestrated principally by the secret society known as the Ku Klux Klan. The North eventually grew tired of imposing Reconstruction by force, and by 1877 white southerners had regained control of all their state governments.
From: Microsoft Encarta 97, "United States/History"