Radical Republicans were a political group during the middle of the 19th century that focused on completely getting rid of the institution of slavery. Along with this, the Radical Republicans also wanted to help in giving African-Americans the civil rights they deserve. This group helped to pass several legislative reforms, including the 13th and 14th amendment.
The 13th amendment was passed thanks to the help of this group and resulted in making slavery in the United States illegal. This group also helped to pass the 14th amendment, which granted citizenship to any individual born on American soil. This citizenship included all the protections guaranteed in the US Constitution.