Final answer:
During Reconstruction, the presidency started out with an ambition to control the process but grew increasingly weak in the face of strong opposition from Congress, particularly the Radical Republicans. The period saw a series of political battles between President Johnson and Congress, leading to his impeachment, and a gradual disintegration of federal commitment to Reconstruction during President Grant's term and its eventual end under President Hayes.
Step-by-step explanation:
During the period of Reconstruction after the American Civil War, the power dynamic between the presidency and Congress underwent significant shifts. Initially, following the assassination of Abraham Lincoln, President Andrew Johnson attempted to steer Reconstruction with a more lenient approach toward the southern states, aiming for a swift reintegration without extensively changing the South's social structure. However, Congress had different ideas, leading to increasing conflicts between Johnson and the legislative body, particularly the Radical Republicans who sought a more thorough transformation of southern society.
Radical Republicans in Congress asserted more control over Reconstruction policies, also in response to the southern states' attempts to maintain old social orders. This tug-of-war for control between the presidency and Congress culminated in Johnson's impeachment, although he ultimately remained in office. With Ulysses S. Grant's presidency, there was an initial effort to continue Reconstruction, but national fatigue and other pressing issues, like the economic depression following the Panic of 1873, led to a gradual retreat from the Reconstruction agenda. By the end of Grant's presidency and into Rutherford B. Hayes', federal commitment to Reconstruction waned significantly, culminating in the removal of the last troops from southern states and the official end of Reconstruction in 1877.