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
Negative income tax for the taxes drawn at the source is flat) which is positive once the income exceeds the tax exemption. If, however, the income is less than the tax exemption, the effective progressive rate actually becomes negative without any involvement by any tax authority. As for the positive progression, only very high incomes would lead to an actual tax rate which is close to the nominal flat tax rate. The tax on tax exemption also can be understood as a tax credit, which is paid back once an income has reached the level of the tax exemption. This level marks the