Constitutional amendments can be proposed by the Congress with a two-thirds majority vote in both the House of Representatives and the Senate. Constitutional amendments can also be proposed by a constitutional convention called for by two-thirds of the State legislatures; however, the first way is the one that has always been used.
It is the Article V of the Constitution the one that prescribes how an amendment, which means an improvement, a correction or a revision to the original content, can become a part of the Constitution.
