Since 1789, Congress has sent 33 constitutional amendments to the states for ratification. Of these, 27 have been ratified. The framers of the Constitution, recognizing the difference between regular legislation and constitutional matters, intended that it be difficult to change the Constitution; but not so difficult as to render it an inflexible instrument of government, as the amendment mechanism in the Articles of Confederation, which required a unanimous vote of thirteen states for ratification, had proven to be. Therefore, a less stringent process for amending the Constitution was established in Article V.