One of the provisions of the Compromise of 1877 was that government U.S. troops would be removed from the South. What did this action lead to?

The Presidential Election of 1876 was a tie. Half of the Electoral votes went to Rutherford B. Hayes and half went to Samuel J. Tilden.
The Democrats agreed to accept the Republican presidential electors (thus assuring that Rutherford B. Hayes would become the next president),as long as he agreed to these terms:

• To withdraw federal soldiers from their remaining positions in the South
• To enact federal legislation that would spur industrialization in the South
• To appoint Democrats to patronage positions in the South
• To appoint a Democrat to the president’s cabinet.

This lead to the end of Reconstruction as the Democrats took over the South.
After Democrats were appointed to office, the Southern state legislature began removing Radical Republican governments and rewriting laws in order to Disenfranchise Freedmen.

-The Rise of Jim Crow Laws-
Governments in the south tried to maintain "pre-war" societal norms through segregation

The 15th Amendment states that
"The right of citizens of the United States to vote shall not be denied or abridged by the United States or by any State on account of race, color, or previous condition of servitude."

While the Southern governments were not denying the freedmen's right to vote, they were creating obstacles.

The Freedmen had to pass Literacy tests and pay poll taxes.
This prevented many African Americans to vote since many had little to no education and little money. This helped more and more Democrats to be voted into office as many whites wanted segregation.
KKK
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Since the federal troops were no longer in the South, the KKK
(Klu Klux Klan) continued to terrorize African Americans. There was no supervision and many African Americans died.