William O. Douglas,
Maricopa County Ariz v. Valley National Bank of Phoenix…
“ On March 20, 1936, Congress enacted a statute providing that shares of preferred stock of national banks 'heretofore or hereafter acquired by' the Reconstruction Finance Corporation 'shall not, so long as Reconstruction Finance Corporation shall continue to own the same, be subject to any taxation by the United States, by any Territory, dependency, or possession thereof, or the District of Columbia, or by any State, county, municipality, or local taxing authority, whether now, heretofore, or hereafter imposed, levied, or assessed, and whether for a past, present, or future taxing period'. ”
