Final answer:
President Johnson's lenient approach to Reconstruction and conflict with Congressional Republicans led to the Radical Republican's control and a military Reconstruction that aimed to protect freedmen's rights. Despite initial efforts and the Fifteenth Amendment, Reconstruction ended with the withdrawal of Union troops in 1877. The clash resulted in Johnson's impeachment and the election of President Ulysses S. Grant.
Step-by-step explanation:
The intransigence of the white South and President Johnson's political bungling played significant roles in shaping the trajectory of Reconstruction after the Civil War. President Johnson's approach, following Lincoln's assassination, aimed for swift reintegration of the Southern states with relatively lenient terms. This stance, coupled with his political missteps and confrontation with Republicans in Congress — who were pushing for greater rights for the freed people and a thorough Reconstruction of the South — led to a significant conflict. Johnson's inability to work collaboratively with Congress and the stubbornness of Southern whites in resisting changes that aimed to eliminate the vestiges of slavery allowed Radical Republicans to take control and implement a military Reconstruction program, which involved federal enforcement of rights for freedmen and rebuilding the Southern political and social systems.
Radical Republicans, advocating for a more equal society, saw the need to push their program forward, leading to the ratification of the Fifteenth Amendment, granting black men the right to vote. Yet, despite these measures, the efforts put forth by the Republicans could not sustain the long-term objective of an interracial democracy that provided equal rights to all citizens, as Reconstruction ended with the withdrawal of Union troops in 1877.
The clash between President Johnson's lenient approach and the Radical Republicans' push for a transformative Reconstruction led to the impeachment of Johnson, though he narrowly avoided removal from office. Ultimately, Ulysses S. Grant won the presidency with the promise of peace, marking a pivotal turn in the nation's effort to reconstruct.