Constitutional Amendment

The formal process by which a constitution's text or meaning is changed. Most constitutions set a higher bar for amendment than for ordinary legislation, such as a supermajority vote in the legislature, ratification by constituent states or provinces, or approval in a referendum, so that the fundamental rules of government are harder to alter than day to day law. The United States Constitution, for example, requires a two-thirds vote in both houses of Congress, or a convention called by two-thirds of the states, followed by ratification by three-quarters of the states. The atlas records no single honest founding year for constitutional amendment as a mechanism, since it is a general structural feature that many separate written constitutions have adopted independently rather than one institution founded at a single moment.