Radical Reconstruction refers to the period following the American Civil War, particularly from 1867 to 1877, when Congress implemented a series of measures aimed at fundamentally transforming Southern society and ensuring civil rights for newly freed African Americans. This approach involved more stringent requirements for Southern states to rejoin the Union and established military oversight in those states to enforce new laws and protect the rights of freedmen. The Radical Republicans believed that without these drastic measures, true equality and democracy could not be achieved in the South.