In 1871, William Holden, the Republican governor of North Carolina, became the first state governor to be impeached

The articles of impeachment claimed he used the militia to oppress the people, to quell what they said was a non-existent insurrection

The insurrection? The KKK

Holden, with backing from President Grant and the U.S. Army, had gone to war with the KKK in NC, which had used violence and intimidation to seized control of 2 counties, lynching a black US Army veteran and assassinating a white Republican state senator.

Holden declared the counties in insurrection & called up the militia. The militia and Federal troops went to work, rounding up Klansmen and driving the KKK underground. But the Klan still used night riders to intimidate the black community. 1870 was an election year.

With the black and Republican voters suppressed, the Democrats surged to power in the state, taking over both houses of the state legislature. In December, Rep Frederick Strudwick brought charges of impeachment against Holden

Strudwick was a Klan leader

After a 3 month trial, Holden was removed from office. The Klan had used violence, voter suppression, and the political system itself to rise to power in the state. A Federal investigation found that although Klan atrocities were common, not a single Klansman was ever charged

Congress passed the Ku Klux Act, giving President Grant power declare KKK-controlled regions in insurrection, and use Federal troops. Which he did with a will. Troops from the 7th Cavalry and 18th Infantry conducted counterinsurgency operations across NC & SC for two years

Hundreds of KKK members were killed or arrested. In SC, however, most of the leaders fled, and returned when US troops left. Lack of enough Federal judges meant cases were tried very slowly. By 1872, the Klan was back in South Carolina

In North Carolina, the Klan was nearly decimated, with leaders caught and imprisoned. But the damage had been done. The KKK's violence ensured conservative Democrat control of the legislature - which passed the Amnesty Act in 1873, absolving night riders of their crimes

This is but one, small, brief snapshot from the Reconstruction era. The entire period from 1866-1876 is filled with examples like this. Reconstruction did not fail: it was defeated by insurgents, who used both violence and political means to achieve their ends

The defeat of Reconstruction is something that every American should know about, as it informs our course as a country even more than the four years of the Civil War, in my opinion.

For a look at the Army's role, I highly recommend this booklet.
https://history.army.mil/html/books/075/75-18/cmhPub_75-18.pdf

By the way, Governor Holden was pardoned by the North Carolina state senate in 2011, in a unanimous vote

So, at least there's that?