The property held by the Edes Home actually and exclusively used and occupied for a home for aged and indigent widows shall while and as long as so actually and exclusively used and occupied, be free from any tax, burden, or assessment, laid or to be laid by the United States or under any authority emanating therefrom. This section shall be and remain at all times subject to repeal, alteration, or amendment by the Congress of the United States.
D.C. Code § 47-1026