Answer:
The United States is a government of enumerated powers. Congress, and the other two branches of the federal government, can only exercise those powers given in the Constitution.
The powers of Congress are enumerated in several places in the Constitution. The most important listing of congressional powers appears in Article I, Section 8 (see left) which identifies in seventeen paragraphs many important powers of Congress. In this section, we consider how several of the enumerated powers of Congress under the original Constitution have been interpreted.