http://pec.lib.wvu.edu/record/P13031943The Oregon country, 1810-1830 : a chapter in territorial expansion.<p> Journal article reprint from: <em>Mississippi Valley Historical Review</em>, v.30:no.1 (1943:June).</p>Ambler, Charles Henry, 1876-1957.United States--Territorial expansion.Northwest, Pacific--History.14256