The federal income tax was ruled unconstitutional by the United States Supreme Court after Congress had passed the tax into law in 1894. It took a constitutional amendment (the 16th, ratified Feb. 25, 1913) to give Congress the official power to "lay and collect" such a tax. A national tax on income (3 percent of annual incomes over $800) had begun in 1862 as a way to pay for the Civil War, but the tax had been rescinded 10 years later.
Source: Famous First Facts, Fifth Ed., by Joseph Nathan Kane, Steven Anzovin, and Janet Podell (H.W. Wilson Co., 1997).
(c) Copyright 2001. The Christian Science Monitor