Henneford v. Silas Mason Co.

Washington taxed the use within the state of personal property purchased elsewhere, to help in-state retailers compete with out-of-state, tax-free sellers, while crediting taxes already paid to Washington or another state. Silas Mason Co. (plaintiff), building a dam in Washington, brought in equipment purchased out of state; the state tax commissioner (defendant) assessed a 2% use tax, which Silas Mason challenged as a Commerce Clause violation.

Whether a state's taxation of the use of chattels purchased in another state violates the Commerce Clause.