Article 4, Section 3, Clause 1
Gouverneur Morris to Henry W. Livingston4 Dec. 1803Life 3:192
A circumstance, which turned up in conversation yesterday, has led me again to read over your letter of the third of November, and my answer of the twenty-eighth. I perceive now, that I mistook the drift of your inquiry, which is substantially whether the Congress can admit, as a new State, territory, which did not belong to the United States when the Constitution was made. In my opinion they cannot.
I always thought that, when we should acquire Canada and Louisiana it would be proper to govern them as provinces, and allow them no voice in our councils. In wording the third section of the fourth article, I went as far as circumstances would permit to establish the exclusion. Candor obliges me to add my belief, that, had it been more pointedly expressed, a strong opposition would have been made.
The Founders' Constitution
Volume 4, Article 4, Section 3, Clause 1, Document 12
The University of Chicago Press
The Life of Gouverneur Morris, with Selections from His Correspondence and Miscellaneous Papers. Edited by Jared Sparks. 3 vols. Boston, 1832.
Easy to print version.