Manitowoc harbor, Wisconsin from survey made betweenteh 14th & 19th of August 1856 by assistant John O'Donoghue, under the direction of Brevet Lieut. Col. J.D. Graham, Major, U.S. Top. Engineers. Superintending Engineer of Lake Michigan Works.
The soundings are in feet & decimals of a foot. "Accompanying Lt. Colonel J.D. Graham's annual report (no. 161) to the Chief Topographical Engineer, dated Chicago, November 15th 1857." "Map G. No. 46." 1 map; 51 x 61 cm This map is in the public domain. Please attribute access and use of this digitized map to the Stephen S. Clark Library, University of Michigan Library.
Graham, J. D. (James Duncan), 1799-1865.,O'Donoghue, John, 1946-,United States. Army. Corps of Topographical Engineers (Corps of Topographical Engineers)