Congressional Reconstruction is often referred to as Radical Reconstruction because it involved big bold plans. Presidential Reconstruction as envisioned by Lincoln and Johnson was meant to be lenient to the former Confederacy in order to encourage reunification and heal the wounds of the Civil War. Radical Republicans in Congress had another plan. They wanted the former rebellious states to be punished and for former slaves to be protected and empowered. In short, Radical Reconstruction was designed to completely remake the South.

Senator Benjamin Wade and Representative Henry Winter Davis proposed their plan in February 1864. The ensuing Wade-Davis Bill was designed to punish the defeated Confederates. This bill would require 50 percent of eligible voters in Southern states to swear loyalty to the Union before their states could be readmitted into the country, unlike the 10 percent proposed by President Lincoln. Unlike proposed Presidential Reconstruction, confiscated Confederate property would not be restored. Military governors were to be appointed throughout the South. This bill was stopped by Lincoln with a pocket veto. However. after Republicans gained a veto-proof majority in 1867, the Wade-Davis Bill became their guide for Reconstruction.

With the Reconstruction Act of 1867, Congress divided the former Confederacy into five zones of military occupation. The Southern states were required to ratify the 14th Amendment. The military remained in those states as long as they were needed to uphold voting rights and protections for former slaves (until the end of Reconstruction).

Radical Reconstructionists also created the Freedman's Bureau. While most Southerners were happy enough to continue exploiting the black population, Radical Reconstructionists used this government agency to protect former slaves. Food and legal assistance were provided, as were educational programs. In this way, Radical Reconstruction attempted to empower former slaves to become active and influential members of their society.

There was extensive, vigorous, deeply racist resistance from white Southerners. Many formed groups such as the Ku Klux Klan to terrorize and intimidate former slaves and anyone who helped them. They frequently murdered black politicians and voters in an attempt to keep them subjugated.

Under Radical Reconstruction, the US Army continued to occupy southern land to protect the newly freed population. There were several episodes in which the army came into direct violent conflict with white supremacy groups. In this way, Congressional Reconstruction was a radical plan because it involved providing rights, resources, and opportunities for formerly enslaved people even to the point of deploying the National Guard.

The proposed plans to rebuild the South after the Civil War differed greatly. President Johnson took the approach that, although the South seceded from the Union, the southern states still retained the right to govern themselves. As a result of his permissive approach, some Southern states began passing laws that were known as "black codes." These laws, with the purpose of restricting the freedom of African Americans in the South, were unacceptable to most Republicans. They were motivated to create their own plans and ideas for rebuilding the South, known as the Radical Republican Plan for Reconstruction.

Driven by the view that African Americans should be seen as equal to whites, Republicans were able to push for legislation that would have been seen as "radical" to many, especially those in the South. For example, the 14th and 15th Amendments to the Constitution were passed, which granted African Americans equality under the law and the right for African American males to vote, respectively. Ratification of the 14th Amendment was a condition that had to be met before states were readmitted to the Union. African American participation in state government and in Congress was another result of the Radical Republican Plan for Reconstruction.

Old habits die hard, and southern whites were not easily swayed. Changes in legislation were not followed by changes in beliefs or philosophy. White supremacy, accompanied by violence, would remain in the South for quite some time.

The Radical Republican plan for Reconstruction was considered radical because, if it would be enacted, it would bring significant changes to the South. The original goals of their plan called for giving all African-American males the right to vote. This was a huge change for southerners, as African-American males weren’t allowed to vote as slaves. It also called for taking away the voting rights of the former leaders of the Confederacy. Another drastic part of their plan called for redistributing land by taking away some of the lands the plantation owners had and giving these lands to the former slaves. Their plan also wanted to provide federal dollars for African-Americans to establish schools.

Some of the accomplishments of their plan also brought significant changes to the South. The Civil Rights Act of 1866 gave African-Americans full citizenship. The 14th amendment stated that all people born in the United States, excluding Native Americans, would be citizens and would have the rights that all citizens have. The military was put in charge of Reconstruction with the passage of the Reconstruction Act of 1867. African-American males were being registered to vote, and they began to vote. Some African-American males were elected to office. The passage of the 15th amendment said that a person couldn’t be denied the right to vote because of their race, or if they had been a slave in the past. Considering the circumstances that many African-Americans faced prior to the end of the Civil War, these changes seemed very extreme to many white southerners.

Of the four plans proposed for Reconstruction, the Radical Republican plan brought about the most change in the South. When their plan was implemented, these changes were so major and altered old ways of doing things in the South so much that to many people they were considered extreme. Thus, the name Radical Reconstruction was an appropriate name for the Reconstruction process.