Article 1, Section 1
Bust out your magnifying glass. We're taking an up-close look at Article 1, Section 1 of the US Constitution.
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.
Congress, and only Congress, has the power to make laws. And the Congress is a bicameral legislative body—that is, it's divided into two chambers, the House and the Senate. ("Bicameral" is just a fancy Latin word that means "two chambers.")