Legal history of income tax in the United States Legal history of income tax in the United States Taxation of income in the United States has been practised since colonial times. Some southern states imposed their own taxes on income from property, both before and after Independence. The Constitution empowered the federal government to raise taxes at a uniform rate throughout the nation, and required that "direct taxes" be imposed only in proportion to the Census population of each state. Federal income tax was first introduced under the Revenue Act of 1861 to help pay for the Civil War. It was renewed in later years and reformed in 1894
Working Tax Credit significant levels of overpayments. In order to reduce the overpayment problem, the income disregard was raised tenfold from £2,500 to £25,000 with effect from 2006/07. Income for tax credit purposes is "in principle" assessed similarly to UK income tax. Thus 'income' (c/f 'taxable income') consists of what the individual receives from gross earned and unearned sources—less allowances for 'expenditures' that would reduce that income. But, unlike income tax, tax credits measure income based on family 'household', rather than the individuals within. Also the effect of "income disregard" —to mask large annual increases in resources from reassessment— weakens comparisons with a