Greenhow was the translator and librarian to the Department of State, a leading authority on the Northwest and a strong advocate for American growth into that region. The map includes all of the western half of North America extending from Russian Possessions in Alaska all the way to Acapulco, Mexico, east to Lake Michigan and west into the Pacific to include the Sandwich Islands. Pre-Fremont geography is depicted in the West. The U.S. - Canadian boundary is undefined, reflecting Greenhow’s advocacy of American claims in the area. Locates Ashley's Lake and Lost and Inconstant Rivers. The Buenaventura River flows into the Swamp Lakes & Is., with the Sacramento River flowing from it. Large inset shows the North Pacific Ocean. A vignette shows the front and back of a medal struck at Boston in 1787 to commemorate the departure of ships Columbia and Washington for an early exploration by the U.S. to the Pacific Northwest. Drawn by David H. Burr, this map was also published as Sen. Doc. 174, 26th. Cong, 1st Sess.

References: Wheat [TMW] #447, Philips (Maps) p. 603

Condition: A

Issued folding, now flat and professionally encapsulated in archival Mylar. Two light spots, still very good.