The Americans contended that they had a title to the whole territory up to the Russian line, and they claimed the entire region drained by the Columbia river. As a compromise, however, they had already, in the negotiations which ended in the Convention of 1827, suggested that the boundary line along the 49th parallel should be continued as far as the Pacific, the navigation of the Columbia river being left open to both nations. This offer was repeated as the controversy went on, with the exception that on the one hand free navigation of the Columbia river was excluded, and on the other the American Secretary of State proposed ‘to make free to Great Britain any port or ports on Vancouver’s Island, south of this parallel, which the British Government may desire’.[243] The counter British proposal was to the effect that the boundary line should be continued along the 49th parallel until it intersected the North-Eastern branch of the Columbia river, and that then the line of the river should be followed to its mouth, giving to Great Britain all the country on the north of the river and to the United States all on the south, the navigation of the river being free to both nations, and a detached strip of coast land to the north of the river being also conceded to the United States, with the further understanding that any port or ports, either on the mainland or on Vancouver Island, South of the 49th parallel, to which the United States might wish to have access, should be constituted free ports. [Sidenote: Settlement of the Oregon boundary question by the Treaty of 1846.] The arguments advanced on both sides, based on alleged priority of discovery and settlement and on the construction of previous treaties, are contained in the Blue Book of 1846, and are too voluminous to be repeated here. The controversy went on from 1842 to 1846; and, when the spring of the latter year was reached, the Americans had withdrawn their previous offer and had refused a British proposal to submit the whole matter to arbitration. There was thus a complete deadlock, but shortly afterwards a debate in Congress showed a desire on the American side to effect a friendly settlement of a dispute which had become dangerous, and, the opportunity being promptly taken by the British Government, a Draft Treaty was sent out by Lord Aberdeen, which was submitted by President Polk to the Senate, who by a large majority advised him to accept it.[244] The Treaty was accordingly signed at Washington on the 15th of June, 1846. By the First Article the boundary line was ‘continued Westward along the said forty-ninth parallel of North latitude to the middle of the channel which separates the continent from Vancouver Island, and thence Southerly, through the middle of the said channel and of Fuca’s Straits, to the Pacific Ocean’,