The event that directly contributed to the end of Reconstruction in the United States was the Compromise of 1877.
After the contentious 1876 presidential election, where Rutherford B. Hayes and Samuel J. Tilden faced off, the outcome was highly disputed. To resolve the election crisis, a compromise was reached: in exchange for Democratic acceptance of Hayes’s presidency, Republicans agreed to withdraw federal troops from the Southern states. This effectively marked the end of Reconstruction.
With the removal of troops, Southern Democrats regained control of state governments, leading to the implementation of Jim Crow laws and the disenfranchisement of African Americans. This shift allowed white Southerners to rebuild their social and economic structures without federal intervention, thus reversing many of the advancements made during Reconstruction.