Map illustrating the plan of the defences of the western & north-western frontier : as proposed by Charles Gratiot in his report of Oct. 31, 1837 / compiled in the U.S. Topographical Bureau under the direction of Col. J.J. Abert, U.S.T.E., by W. Hood.Hood, Washington1837]In upper right margin: Mil. Aff., Vol. VII, No. 753-B.Includes distance table.Prime meridian: Washington.cartographic