Federal soldiers also intimidated voters into voting Republican by menacing them at the polls. As Lincoln biographer David Donald has written, "Under the protection of Federal bayonets, New York went Republican by seven thousand votes" in 1864.
The Republican Congress even created three new states—Kansas, West Virginia, and Nevada—to help rig the 1864 election in favor of Lincoln, so concerned were they over pervasive antiwar sentiment and massive desertions from the federal army.
During "Reconstruction" (1865–1877) the Republican Party held a monopoly of power that was so complete, historian Richard Bensel observed in Yankee Leviathan, that the closest parallels to that situation are "the PRI in Mexico, the Congress Party in India, and the Bolsheviks in the early years of the Soviet Union."
https://mises.org/library/origins-american-vote-fraud