Even in the smallest of Indian locales, the divisions of geography and nationalism are played out on a micro scale.
The last one was endorsed on May 7, 1992. Though there are 27 amendments to the Constitution of the USA, only 26 of them are in function. The point is that the 21 amendment annulled the 18th one. The procedure of amending is described in Article V of the U.S. Constitution.
Only the Congress or the states can actually CHANGE the Constitution. The only way to actually CHANGE it is via a constitutional amendment. Congress or the states can initiate that, and the amendment has to be ratified by a fixed number of states before it takes effect. We've got 27 amendments, the most recent as of 1992. The Constitution can also be changed at a Constitutional Convention, but none have been done that way since the 1700s. There was a movement in the 1990s to call a Convention to make a Balanced Budget Amendment, but it never succeeded. The Supreme Court can INTERPRET the Constitution, but can't change it.