Final answer:
The 16th amendment allowed for the imposition of income tax at the national level. This amendment authorized the federal government to directly tax the incomes of individuals. The income tax was a progressive tax.
Step-by-step explanation:
The 16th amendment, enacted at the national level, allowed for the imposition of income tax. This amendment authorized the federal government to directly tax the incomes of individuals. The income tax was a progressive tax, which meant that higher rates of taxation were applied to individuals with higher incomes.