DOUGLAS GINSBURG, Federal Judge, U.S. Court of Appeals, D.C. Circuit:
27 so far. The first ten were passed when the ink was barely dry on the Constitution. We call those ten the Bill of Rights. They are a guarantee of our fundamental freedoms.

Since then, we’ve amended the Constitution seventeen times: about once every 13 years or twice a generation. But the last one -- took more than two hundred years to be passed.
The Twenty-seventh Amendment says if Congress votes itself a pay raise, then the raise can’t take effect until after the next election. This amendment was actually proposed in 1789, along with the other ten amendments that became the Bill of Rights. But this amendment was ratified by only six states. While others were ratified by the necessary three-quarters of the states. But the Congress didn’t put a deadline on ratification.
Fast forward to 1982, when a sophomore at the University of Texas stumbled across the forgotten amendment -- and wrote a paper arguing it could still be passed. He got a C on his paper – which irked him so much, he decided to do something about it, he wrote letters to state lawmakers urging them to ratify the amendment.
The timing was finally right. The public was fed up with the Congress’s high pay and perks. In 1992, the Twenty-seventh Amendment was ratified – 202 years after it had been proposed.