U.S. ConstitutionArticle I — The Legislative BranchSubarticle 10Section 1
No State shall enter into any Treaty, Alliance, or Confederation; grant Letters of Marque and Reprisal; coin Money; emit Bills of Credit; make any Thing but gold and silver Coin a Tender in Payment of Debts; pass any Bill of Attainder, ex post facto Law, or Law impairing the Obligation of Contracts, or grant any Title of Nobility.
Use as reference
Lexinter.net | U.S. Const. art. I, § 10, cl. 1 | https://laws.lexinter.net/constitution/us/article-1/section-10/clause-1