When title to the site of the Andrew Johnson Homestead and the site of the tailor shop in which Andrew Johnson worked (now owned and administered by the State of Tennessee), located in Greeneville, Tennessee, together with such buildings and property located thereon as may be designated by the Secretary of the Interior as necessary or desirable for national historic site purposes shall have been vested in the United States, said area and improvements, if any, together with the burial place of Andrew Johnson, now administered as a national cemetery, shall be designated and set apart by proclamation of the President for preservation as a national historic site for the benefit and inspiration of the people and shall be called the "Andrew Johnson National Historic Site."