One of the first tasks of the administration was to restore the commercial relations which had been so disturbed by the Napoleonic wars. Algiers had taken advantage of the War of 1812 to capture American vessels. In 1815 the Dey was compelled on the quarter-deck of Decatur's ship to sign a treaty of peace and amity. All our commercial treaties had disappeared in the war, and had to be painfully renewed. In 1815 a commercial convention was made with Great Britain, and in 1818 the fishery privileges of the United States were reaffirmed. The West India trade was still denied, but a retaliatory act brought Great Britain to terms, and it was opened in 1822. 124. TERRITORIAL EXTENSION (1805-1819). [Sidenote: Northern boundary.] [Sidenote: Oregon.] [Sidenote: Boundary treaty.] The administration inherited two serious boundary controversies, one with England, and another with Spain. Some progress had been made toward running the northeast boundary, till in 1818 the commissioners disagreed. The northwest boundary had now come to be more important. A few months before the annexation of Louisiana, Jefferson had sent an expedition to explore the country drained by the Columbia River, which had been discovered by a Boston ship in 1791. This expedition, under Lewis and Clark, in 1805 reached tributaries of the Columbia and descended it to its mouth, anticipating a similar English expedition. Nevertheless, the Hudson's Bay Company established trading-posts in the region. Monroe settled the difficulty for the time being by a treaty with Great Britain in 1818, providing that the disputed region lying between the Rocky Mountains and the Pacific Ocean and extending indefinitely northward should be jointly occupied by both countries. At the same time the northern boundary was defined from the Lake of the Woods to the Rocky Mountains. [Sidenote: West Florida.] [Sidenote: Spanish treaty.]