The Compromise of 1877
basically brought an end to the period of Reconstruction
after the American Civil War
Let's set the stage.
The time is 1876, the candidate on the Republican side was Rutherford B. Hayes, representing the Democrats was Samuel L. Tilden. The election is very close, Tilden leads in the popular vote but the count from four states, representing a total of 20 votes in the Electoral College, is disputed. The problem, no precedent has been set for dealing with contested votes. Partisanship is rampant. Eventually, in 1877, Congress sets up a special electoral commission with an equal number of Democrats and Republicans to decide the disputed votes (does any of this sound at all familiar?). The tie braking member of the commission is swayed to the Republican side and the commission then awards all disputed votes to Hayes. He wins the election with 185 electoral votes to Tilden's 184.
The Compromise came about as a result of the Democrats, mostly Southerners, threat to prevent the commission from reporting via a filibuster. The Republicans, mostly Northerners, get the Democrats to agree to abandon the filibuster by offering the following:
The withdrawal of all federal troops from the South.
The appointment of at least one Southerner to Hayes's cabinet.
Economic incentives and benefits aimed to industrialize the South
The fallout of the Compromise of 1877 was that with the troop withdrawal, the efforts to promote racial equality in the South could no longer be federally enforced and was essentially abandoned.