Resolution of Congress21 Feb. 1787Documentary History 4:78
Resolved that in the opinion of Congress it is expedient that on the second Monday in May next a Convention of delegates who shall have been appointed by the several states be held at Philadelphia for the sole and express purpose of revising the Articles of Confederation and reporting to Congress and the several legislatures such alterations and provisions therein as shall when agreed to in Congress and confirmed by the states render the federal constitution adequate to the exigencies of Government & the preservation of the Union.
The Founders' Constitution
Volume 4, Article 7, Document 1
The University of Chicago Press
Documentary History of the Constitution of the United States of America, 1786--1870. 5 vols. Washington, D.C.: Department of State, 1901--5.