This was the status of Oregon when Spain ceded Louisiana to France in 1800, and when France ceded the same territory to the United States in 1803; and the matter of first concern to the United States was the question whether Louisiana contained Oregon or any part of it. It is probable that President Jefferson thought it did, since the Lewis and Clark expedition, sent out by him to examine the new purchase, crossed the Rockies, discovered the sources of the Columbia River, followed this stream to the Pacific, and made report thereof to the President. But if he did, he was certainly mistaken. It is true that Louisiana had no western boundary positively fixed by any agreement between the Powers, but the general principles of international law, to which recourse must always be had in the absence of specific agreements, made the water shed of the Mississippi the western boundary, and the Treaty of Utrecht, of 1713, to which France and Great Britain were parties, made the forty-ninth parallel of latitude the northern boundary, westward from the Lake of the Woods. [Illustration: OREGON, as Determined by the Treaty of 1846.] [Sidenote: Astoria.] The founding of Astoria, in 1811, on the south bank of the Columbia River, about nine miles from its mouth, is also evidence that the Government of the United States thought it had a claim upon Oregon as a part of Louisiana, since the undertaking {313} proceeded upon an understanding between Mr. John Jacob Astor and the Government. [Sidenote: The joint occupation agreement of 1818.] The British Government now did a thing which seemed to acknowledge a claim of some sort by the United States upon Oregon, so far as Great Britain could do so. Having taken forcible possession of Astoria in the War of 1812, it restored the place, at the close of the War, to the possession of the United States; and in a convention, concluded on October 18th, 1818, the two Powers agreed upon the forty-ninth parallel of north latitude as the boundary between their territories, from the Lake of the Woods to the Rocky Mountains, and upon joint occupation, as it was termed, in all territories and waters claimed by either party in North America west of the Rocky Mountains, without prejudice to any claims which either party might have to any part of the said territory, or to any claims which any other Power might have to it, or to any part of it. This agreement was to run for ten years. [Sidenote: Spain's claims on Oregon ceded to the United States.]