Oregon: The Claim of the United States to Oregon, as Stated in the Letters of the Hon. J.C. Calhoun and the Hon. J. Buchanan (American Secretaries of State) to the Right Hon. R. Pakenham, Her Britannic Majesty's Plenipotentiary : with an Appendix Containing the Counter Statement of Mr. Pakenham to the American Secretaries of State : and a Map Showing the Boundary Line Proposed by Each Party