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 in the form of the Wilson-Gorman tariff.
Legal challenges centered on whether the income tax then in force constituted a "direct tax". In the Springer v. United States case of 1881, the Supreme Court upheld the tax regime then in force. A 1894 statute was ruled unconstitutional in the case of Pollock v. Farmers' Loan and Trust Company. In response, the Sixteenth Amendment, proposed in 1909 and becoming law in 1913, cancelled the "apportionment" requirement for income taxes. Federal income tax was thereupon reintroduced in the Revenue Act of 1913. In the case of Brushaber v. Union Pacific Railroad Company (1916), the 1913 Act was ruled to be constitutional. A separate excise tax was also imposed on corporations.
Subsequent legal actions were concerned with what should be counted as "income" under the 1913 Act. In Eisner v. Macomber (1920), the Supreme Court ruled that proportionate stock dividends were not taxable as income, on the grounds that the dividend income was not "severable" from the capital holding from which it was derived. Later decisions, however, have tended to limit this view of "severability," and to uphold the federal statutes as exertions of the power of Congress to tax.
History through 1916
Early history
The first attempt to tax income in the United States was in 1643 when several colonies instituted a "faculties and abilities" tax. Tax collectors would literally go door to door and ask if the individual had income during the year. If so, the tax was computed on the spot. The income tax raised little revenue, and was viewed as a supplement to more traditional forms of property taxation.
Constitutional provisions
Article I, Section 8, Clause 1 of the United States Constitution (the "Taxing and Spending Clause"), specifies Congress's power to impose "Taxes, Duties, Imposts and Excises," but Article I, Section 8 requires that, "Duties, Imposts and Excises shall be uniform throughout the United States."
In addition, the Constitution specifically limited Congress' ability to impose direct taxes, by requiring that direct taxes be imposed in proportion to each state's census population. It was thought that head taxes and property taxes (slaves could be taxed as either or both) were likely to be abused, and that they bore no relation to the activities in which the federal government had a legitimate interest. The fourth clause of section 9 therefore specifies that, "No Capitation, or other direct, Tax shall be laid, unless in Proportion to the Census or enumeration herein before directed to be taken."
Taxation was also the subject of Federalist No. 33 penned secretly by the Federalist Alexander Hamilton under the pseudonym Publius. In it, he explains that the wording of the "Necessary and Proper" clause should serve as guidelines for the legislation of laws regarding taxation. The legislative branch is to be the judge, but any abuse of those powers of judging can be overturned by the people, whether as states or as a larger group.
Early colonial and state income taxes
In the early 18th century and well into the 19th century, a number of the southern colonies and states adopted an income tax modeled on the tax instituted in England. The British theory was that you tax the income from property, and not the property itself; thus, sales of property were not subject to taxation.
First income tax law
In order to help pay for its war effort in the American Civil War, the United States government imposed its first personal income tax, on August 5, 1861, as part of the Revenue Act of 1861. Tax rates were 3% on income exceeding $600 and less than $10,000, and 5% on income exceeding $10,000. This tax was repealed and replaced by another income tax in the Revenue Act of 1862.