Constitution of the United States of America
Article V: Amending Constitution
Article 5, Section 0:  Requirements for Amending

 The Congress, whenever two thirds of both Houses shall
deem it necessary, shall propose Amendments to this
Constitution, or, on the Application of the Legislatures of two
thirds of the several States, shall call a Convention for proposing
Amendments, which, in either Case, shall be valid to all Intents
and Purposes, as Part of this Constitution, when ratified by the
Legislatures of three fourths of the several States,

5.0.2  or by Conventions in three fourths thereof, as the one or
the other Mode of Ratification may be proposed by the Congress;

5.0.3  Provided that no Amendment which may be made prior to
the Year One thousand eight hundred and eight shall in any
Manner affect the first and fourth Clauses in the Ninth Section of
the first Article;

5.0.4  and that no State, without its Consent, shall be deprived of
its equal Suffrage in the Senate.