Article I Section 1

All Legislative Powers herein granted shall be vested in a Congress of the United States, which shall consist of a Senate and House of Representatives.

This one is pretty simple, but like all parts of the constitution important. The framers separated government into three branches. granting the power to pass laws to the Congress, the power to administer laws to the President, and the power to interpret laws to the courts. These powers are set out in Article I. There are some places where these powers overlap(congress approving presidential appointments for instance).

The separation of the law making body into house and senate represented a compromise. Rural states have few residents hence fewer representatives, but still get two senators. While populous states have many representatives but still only two senates.

Article I Section 1 also points out the important point that all federal powers are laid out in what is written in the constitution. The so called “enumerated powers,” these are the things that the federal government can do, if its not in the constitution then its up to the states.