The first federal income tax was adopted as part of the Revenue Act of 1861. The tax lapsed after the American Civil War. Subsequently enacted income taxes were held to be unconstitutional by the Supreme Court in "Pollock v. Farmers' Loan & Trust Co." because they did not apportion taxes on property by state population. In 1913, the Sixteenth Amendment to the United States Constitution was ratified, permitting the federal government to levy an income tax on both property and labor.