The United States War Revenue Act of 1917 greatly increased federal income tax rates while simultaneously lowering exemptions.
Contents
The 2% bracket had previously applied to income below $20,000. That amount was lowered to $2,000. The top bracket (on income above $2 million) was raised from 15% to 67%.
The act was applicable to incomes for 1917.
War Income Tax for Individuals
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.
Inflation-adjusted numbers
Corrected for inflation by CPI:
References
War Revenue Act of 1917 Wikipedia(Text) CC BY-SA