Article 1, Section 8, Clause 11
Document 14
The Schooner Exchange v. McFaddon
7 Cranch 116 1812
The Founders' Constitution
Volume 3, Article 1, Section 8, Clause 11, Document 14
http://press-pubs.uchicago.edu/founders/documents/a1_8_11s14.html
The University of Chicago Press