"Thus in Mobile County v. Kimball, 102 U. S. 691, 26 L. ed. 238, it is held that 'commerce with foreign countries and among the states, strictly considered, consists in intercourse and traffic, including in these terms navigation and the transportation and transit of persons and property;' and in Gloucester Ferry Co. v. Pennsylvania, 114 U. S. 196, 203, 29 L. ed. 158, 161, 1 Inters." . . . . .