Final answer:
Radical Republicans opposed Lincoln's Reconstruction plan because it offered amnesty to nearly all Confederates.
Step-by-step explanation:
Radical Republicans opposed Lincoln's Reconstruction plan because it offered amnesty to nearly all Confederates who would swear allegiance to the U.S. The Radical Republicans believed that the Southern states should be punished for leaving the Union and that the plan was too lenient on them. They also disagreed with Lincoln's approach of allowing the Southern states back into the Union without treating them as military districts.
Learn more about Lincoln's Reconstruction plan