[AP Government] How do I do MLA citations for articles and sections of the US Constitution?

I'm writing some stuff for government class, and I assume that the teacher would want me to cite my sources. I have this sentence written: Regarding the legislative branch, the Constitution states that the members of the House of Representatives are “chosen every second Year by the People of the several States.”

How would I do the parenthetical citation after the quote? What would I put on the works cited?