How did Radical Reconstruction differ from Presidential Reconstruction?

By 1866, some Northerners were already unhappy with the president's conduct of Reconstruction. They believed that President Johnson was resisting, rather than helping the effort to enable African-Americans to exercise their freedoms. Dozens of former Confederates were already returning to positions of power in the South, and even being elected to serve in Congress and the Senate. Violence against black Southerners suggested that some white Southerners were unwilling to accept blacks' equality. In the November elections, Radical Republicans captured a majority in both the House of Representatives and the Senate. When these Republicans were sworn in the following year, the second phase of Reconstruction began.

Because this phase was directed by Radical Republicans in the U.S. Congress, it became known as Radical Reconstruction or Congressional Reconstruction. Its leaders, Representative Thaddeus Stevens of Pennsylvania and Senator Charles Sumner of Massachusetts, were determined to stop white Southern resistance to Reconstruction and the ensure the equality and freedom of black Southerners.