The Radical Republicans were a faction within the Republican Party during the mid-19th century, particularly active during and after the American Civil War. They believed in strong measures to ensure the rights of newly freed slaves and sought to transform Southern society. Their main goal was to secure civil rights and political power for African Americans, often clashing with more moderate politicians. Led by figures like Thaddeus Stevens and Charles Sumner, the Radical Republicans pushed for the passage of the Reconstruction Acts. These laws aimed to rebuild the South and enforce civil rights, leading to significant changes in American society. Their efforts laid the groundwork for future civil rights advancements.