From the Original Draft of the U.S. Constitution.
Purpose of Taxation.

(Entire Text of the Original Draft)
VII.

Sect. 1. The Legislature of the United States shall have the power to lay and collect taxes, duties, imposts and excises;
.......... To regulate commerce with foreign nations, and among the several States;
.......... To establish an uniform rule of naturalization throughout the United States;
.......... To coin money;
.......... To regulate the value of foreign coin;
.......... To fix the standard of weights and measures;
.......... To establish post-offices;
.......... To borrow money, and emit bills on the credit of the United States;
.......... To appoint a Treasurer by ballot;
.......... To constitute tribunals inferior to the supreme court;
.......... To make rules concerning captures on land and water;
.......... To declare the law and punishment of piracies and felonies committed on the high seas, and the punishment of counterfeiting the coin of the United States, and of offences against the law of nations;
.......... To subdue a rebellion in any State, on the application of its Legislature;
.......... To make war;
.......... To raise armies;
.......... To build and equip fleets;
.......... To call forth the aid of the militia, in order to execute the laws of the Union, enforce treaties, suppress insurrections, and repel invasions;

And to make all laws that shall be necessary and proper for carrying into execution the foregoing powers, and all other powers vested, by this Constitution, in the government of the United States, or in any department or officer thereof.