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, or by conventions in three-fourths thereof, as the one or the other mode of ratification may be proposed by the Congress: Provided, that no amendment which may be made prior to the year 1808, shall in any manner affect the first and fourth clauses in the ninth section of the first article; and that no state, without its consent, shall be deprived of its equal suffrage in the Senate.
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https://avalon.law.yale.edu/18th_century/preamble.asp Historical text: public domain in the United States. Source attribution retained; modern website editorial material excluded. Source transcription extracted and structurally checked; not collated against page images. Preamble and Articles I–VII. Source headings and amendment annotations retained; signature table excluded. Article pages are separately recorded in acquisition.json. Paragraph numbers are editorial, not constitutional clause numbers.