What is the specific law that established a personal income tax in the USA?
The legislation you want would depend on what you think is the “first” income tax. The very first income tax on individuals was created by the Revenue Act of 1861 to fund the Civil War. It did not last long after the war. The Wilson-Goram Act of 1894 established the second income tax, but was declared unconstitutional. The first individual income tax imposed after ratification of the 16th Amendment was imposed by the Revenue Act of 1913, Section II, A. subdiv. 1, 38 Stat. 114, 166. The 1913 Revenue Act provided in part, “Subdivision 1. That there shall be levied, assessed, collected and paid annually upon the entire net income arising or accruing from all sources in the preceding calendar year to every citizen of the United States, whether residing at home or abroad, and to every person residing in the United States, though not a citizen thereof, a tax of 1 per centum per annum upon such income, except as hereinafter provided; and a like tax shall be assessed, levied, collected, and pa
