"McCulloch v. Maryland" and "Osborn v. Bank of the United States", 22 U.S. 738 (1824), had both established that states could not levy taxes on the federal government.But "James v. Dravo Contracting Co." established the "legal incidence test," under which the economic impact of the tax was not the critical point but whether the tax was levied statutorily on the federal government or not.