In order to help pay for its war effort in the American Civil War, Congress imposed the first federal income tax in U.S. history through passage of the Revenue Act of 1861. The act created a flat tax of three percent on incomes above $800 ($ in current dollar terms). This taxation of income reflected the increasing amount of wealth held in stocks and bonds rather than property, which the federal government had taxed in the past. The Revenue Act of 1862 established the first national inheritance tax and added a progressive taxation structure to the federal income tax, implementing a tax of five percent on incomes above $10,000. Congress later further raised taxes, and by the end of the war, the income tax constituted about one-fifth of the revenue of the federal government. To collect these taxes, Congress created the Office of the Commissioner of Internal Revenue within the Treasury Department. The federal income tax would remain in effect until its repeal in 1872.