This section is from the book "The Constitutional Law Of The United States", by Westel Woodbury Willoughby. Also available from Amazon: Constitutional Law.
So long as the Indians form distinct communities occupying clearly defined territories, even though those territories be within the borders of the States, intercourse with them is a matter subject to federal regulation,80 and this federal power of regulation extends to the prohibition of sales to Indians within a State and beyond the borders of the Indian Reservation.81 The federal control of commerce with the Indians, given by the Commerce Clause, is thus seen to be supplemented by the general jurisdiction of the National Government over Indians as wards of the Nation.82
79 Hanley v. Kansas City S. Ry. Co.. 187 U. S. 617; 23 Sup. Ct. Rep. 214; 47 L. ed. 333: Stoutenburgh v. Hennick. 129 U. S. 141; 9 Sup. Ct. Rep. 256; 32 L. ed. 637. These cases do not, however, squarely decide this point. Cf. Michigan Law Review, II. 468.
80 United States v. Kagama, 118 U. S. 375; 6 Sup. Ct Rep. 1109; 30 L. ed. 228; United States v. Holliday, 3 Wall. 407; 18 L. ed. 182.
81 United States v. Holliday. 3 Wall. 407; 18 L. ed. 182.
82 See Chapter XX (The Legal Status Of Indians) for a more detailed treatment of this subject.