The United States War Revenue Act of 1917 greatly increased federal income tax rates while simultaneously lowering exemptions.
The top bracket (on income above $2 million) was raised from 15% to 67%.
In addition to the Normal Tax and an Additional Tax levied against the net income of individuals in the Revenue Act of 1916 a "like normal" tax and a "like additional" tax were levied against the net income of individuals as shown in the following table.
Payments subject to reporting included payments of interest, rent, salaries, wages, premiums, annuities, compensation, remuneration, emoluments, or other fixed or determinable gains, profits, and income.
The payor was required to report the name and address of the payee and the total amount of payments on Form 1099 and sent to the Internal Revenue Service by March 1 of the year following the payments.