[In this department of the _Quarterly_ there will appear material of the nature of primary sources for the history of the Pacific Northwest. The more extended documents, however, and collections having a unity will be reserved for the series, “Sources of the History of Oregon.”] _Correspondence of John McLoughlin, Nathaniel J. Wyeth, S. R. Thurston, and R. C. Winthrop, pertaining to claim of Doctor McLoughlin at the Falls of the Willamette—the site of Oregon City._ The following correspondence was published in the Milwaukee Star, April 10, 1850. The files of this paper are exceedingly scarce. The original copies of the letters were probably destroyed. A knowledge of their contents is essential to an understanding of very important, though not creditable, transactions in Oregon’s history. These letters also are an addition to the Wyeth material that the society has been making accessible to students of American history. CHICOPEE, Mass., Nov. 16, 1850. _Capt. Nath. J. Wyeth_: MY DEAR SIR—You will excuse me, I am sure, when I assure you I am from Oregon, and her delegate to the Congress of the United States, for addressing you for a purpose of interest to the country which I belong. I desire you to give me as correct a description as you can at this late period, of the manner in which you and your party, and your enterprise in Oregon, were treated by the Hudson’s Bay Company, and particularly by Doc. John McLoughlin, then its Chief Factor. This Dr. McLoughlin has, since you left the country, rendered his name odious among the people of Oregon, by his endeavors to prevent the settlement of the country, and to cripple its growth. Now that he wants a few favors of our Government, he pretends that he has been the long-tried friend of Americans and American enterprise west of the mountains. Your early reply will be highly appreciated, both for its information, and your relation to my country. I am, sir, yours very truly, S. R. THURSTON. CAMBRIDGE, Nov. 21, 1850. _Hon. Sam’l R. Thurston_: