603 (1870), was a United States Supreme Court case in which the Chief Justice of the United States, Salmon P. Chase, speaking for the Court, declared certain parts of the Legal Tender Acts to be unconstitutional.

It also found that the treatment of notes as legal tender represented an impairment to enforcing the obligations of contracts.

The Court found no similar constraint upon the federal government, but it held that such an impairment would violate the spirit of the Constitution.

It continued that making United States Notes legal tender was unnecessary to fighting a war.

The majority opinion was explicitly overruled by Knox v. Lee and other Legal Tender Cases, 79 U.S. (Wall.