1862
Legal Tender Act
Congress authorizes United States Notes. The paper dollar floats below gold.
In February 1862 the Legal Tender Act authorized United States Notes — greenbacks — as legal tender. The Union paid for the war in paper the Treasury would not redeem in gold on demand.
In New York that paper traded at a gold premium: the market’s measure of notes against metal. The date set to close that gap was 1 January 1879. This page is the authorization, not the resumption.