Article I, Section 2 of the U.S. Constitution requires that the House of Representatives "shall be apportioned among the several States---according to their respective Numbers," and that "each State shall have at least one Representative." That section also includes the requirement that an enumeration of the population for the purpose of apportioning the House be conducted every ten years. The quoted words obviously do not explicitly state what method should be used for apportionment, and for over 200 years the issues of which is the "best" method and which methods are constitutional have been debated. In fact, apportionment of the House was the subject of George Washington’s first veto.