American Civil War: In order to help pay for the war effort, the United States government levies the first income tax as part of the Revenue Act of 1861 (3% of all incomes over US$800; rescinded in 1872).

The American Civil War was a civil war in the United States between the Union and the Confederacy, which was formed in 1861 by states that had seceded from the Union to preserve slavery in the United States. The South saw slavery as threatened because of the election of Abraham Lincoln and the…