11 Wall. (78 U.S.) 113 (1871), argued 3 Feb. 1871, decided 3 Apr. 1871 by vote of 8 to 1; Nelson for the Court, Bradley in dissent. Collector v. Day was one in a line of cases involving intergovernmental tax immunities, and, as such, traced its origins to the latter part of Chief Justice John Marshall's opinion in McCulloch v. Maryland (1819), which held that a state could not tax an instrumentality of the federal government. Following this reasoning, the Court had held in Dobbins v. Erie County (1842) that a state could not tax the income of a federal officer. Collector v. Day was the reciprocal of Dobbins, holding that the federal government could not tax the income of a state judge. Justice Samuel Nelson relied on the Tenth Amendment and on doctrines of dual sovereignty to hold that the state and federal governments were independent of each other and that the states retained all aspects of sovereignty not delegated to the federal government. Consequently, he reasoned, the federal government could not tax essential instrumentalities of the states. The Day doctrine was weakened by the Court's decision in Helvering v. Gerhardt (1938) and finally explicitly overruled in Graves v. O’Keefe (1939).
William M. Wiecek