Actually Mr. Shedlock, there is already a law on the books that makes gold and silver the ONLY legal money in the entire United States. That law is Article I, Section 10 of the Constitution of the United States of America. It is the section that defines the Powers Prohibited of the Several States, and it states:
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.
But since the Federal Government ignores the Constitution, we have something other than gold