by John Marshall Harlan

“ The debt is property in his hands constituting a portion of his wealth, from which he is under the highest obligation, in common with his fellow-citizens of the same State, to contribute for the support of the government whose protection he enjoys.
That debt, although a species of intangible property, may, for purposes of taxation, if not for all others, be regarded as situated at the domicile of the creditor. It is none the less property because its amount and maturity are set forth in a bond. ”

“ The mortgage is but a security for the debt, and, as held in State Tax on Foreignheld Bonds (supra) , the right of the creditor 'to proceed against the property mortgaged, upon a given contingency, to enforce by its sale the payment of his demand, . . . has no locality independent of the party in whom it resides. It may undoubtedly be taxed by the State when held by a resident therein,' &c. Cooley on Taxation, 15, 63, 134, 270. The debt, then, having its situs at the creditor's residence, both he and it are, for the purposes of taxation, within the jurisdiction of the State. ”

“ Plainly, therefore, our only duty is to inquire whether the Constitution prohibits a State from taxing, in the hands of one of its resident citizens, a debt held by him upon a resident of another State, and evidenced by the bond of the debtor, secured by deed of trust or mortgage upon real estate situated in the State in which the debtor resides. ”