Who proposes amendments for the constitution?

Normally the Congress proposes and passes amendments to the Constitution. This requires a two-thirds vote of the members present in Congress (and assumes a quorum is present). The passed amendment must then be ratified by 2/3 of the states (legislatures or conventions).

However, Article 5 of the Constitution also allows states to propose amendments, forming a convention by the vote of at least 2/3 of the state legislatures of the country. This convention would produce an amendment in the same way as the Congress, and it would then be considered for ratification by each individual state as usual. This method has never been utilized.