How did the federal government attempt to fix each of the primary issues of Reconstruction?

Reconstruction was the period after the Civil War, from 1865 to 1877 in American history. It dealt with the process of readmitting former Confederate states to the Union. There were three key issues:
1. Would the executive or legislative branch run Reconstruction?
2. How would black people in the postwar South be protected from violence?
3. How would freed slaves transition into their new lives?
President Abraham Lincoln was assassinated in 1865, and he was replaced by Vice President Andrew Johnson. Both men wanted a fairly lenient treatment of the South. However, Congress wanted a much harsher approach. Ultimately, Congress prevailed by impeaching and weakening Johnson. Therefore, the legislative branch ultimately controlled Reconstruction.
Second, black people were badly treated in the postwar South. The KKK was created in 1866; Freedman were intimidated and attacked. The federal government tried to protect black people with the Enforcement Acts (1870–1871), but these efforts were ineffectual. In 1873, in Louisiana, a mob killed eighty-one black people.
Third, former slaves had difficulty transitioning from servitude to freedom. They were given their freedom, but they had no resources to earn a living. The government set up the Freedmen's Bureau to educate, assist, and reunite families. Some freedmen became politically and socially active, but their gains did not endure.
In the end, the North grew tired of Reconstruction. In the aftermath of the disputed election of 1876, shady dealings led to the withdrawal of all troops and the end of Reconstruction. After 1877, black people lost most all their already-meager rights in the South.