Article 1, Section 10, Clause 2
SEE ALSO:
Generally 1.8.3 (commerce); 1.8.4 (bankruptcy)
Records of the Federal Convention, Farrand 2:135, 143, 158--59, 169, 437, 577, 583, 597, 605
James Iredell, Marcus, Answers to Mr. Mason's Objections to the Constitution, 1788, Pamphlets 366--67
The Founders' Constitution
Volume 3, Article 1, Section 10, Clause 2, Introduction
http://press-pubs.uchicago.edu/founders/documents/a1_10_2s12.html
The University of Chicago Press