The "White terror" of which you speak were organizations such as the Knights of the Ku Klux Klan, the White Camellia, and in South Carolina the Red Shirt Campaign. These organizations were comprised of white Democrats who used various methods of terror to frighten both Blacks and Republican whites from participating in politics, particularly in voting. To the discredit of the Reconstruction Congress, the Federal Government virtually abandoned attempts to rehabilitate former slaves.
The Compromise of 1877 was the result of the disputed election of that year. Rival governments in the South sent rival electoral votes to Congress such that no one had a majority in the Electoral college. A committee of fifteen comprised of five members each of the House, Senate, and Supreme Court was formed to resolve the issue. By terms of the Compromise, Rutherford B. Hayes was declared the winner of the election, in exchange for which federal troops were removed from the South, and reconstruction came to an end, even though its work was not finished. Former slaves were free, but the Fourteenth Amendment notwithstanding, had few freedoms and civil rights. They were hardly better off because they had been abandoned by the North in the face of white terrorism.