Mexico, and on the north, by the regions of eternal frost". Both saw the war as part of a divine plan to unify the US and Canada, Johnson being its leading exponent. Others considered annexation a matter of domestic economic and political necessity. Tennessee Congressman Felix Grundy was one of many who saw it as essential to preserve the balance between slave states and free states that might be disrupted by the incorporation of territories in the Southeast acquired in the 1803 Louisiana Purchase. Control of the St. Lawrence River, the major outlet for trade between Europe and the Great Lakes region, was a long-standing American ambition, going back to the early years of the Revolutionary War, and supported by powerful economic interests in the North-West. Madison also viewed it as a way to prevent American smugglers using the river as a conduit for undercutting his trade policies. All these groups assumed American troops would be greeted as liberators, guaranteeing an easy conquest. Thomas Jefferson believed taking "...Canada this year, as far as...Quebec, will be a mere matter of marching, and will give us the experience for the attack on Halifax, the next and final expulsion of England from the American continent". In 1812, Canada had around 525,000 inhabitants, two thirds of whom were French-speakers living in Quebec. Upper Canada, now southern Ontario, had a population of less than 75,000, primarily Loyalist exiles and recent immigrants from the Northeastern United States. The former were implacably hostile to the United States; the latter largely uninterested in politics and their loyalties unknown; unlike the Texas annexation in 1845, they were too few to provide a critical mass of pro-American support, while many followed their Loyalist neighbours and joined Canadian militia. Absence of local backing prevented American forces from establishing a foothold in the area, and of ten attempts to invade Upper Canada between 1812 and 1814, the vast majority ended in failure. U.S. policy in the Northwest Territory The Northwest Territory, a region between the Great Lakes, the Ohio River, Appalachians, and Mississippi, was a long-standing source of conflict in 18th and early 19th-century North America. This arose when settlers from the Thirteen Colonies moved onto lands owned by the indigenous inhabitants, a collection of Algonquian and Iroquoian-speaking peoples, chiefly the Shawnee, Wyandot, Lenape, Miami, Potawatomi, Kickapoo, Menominee, and Odawa. When Pontiac's War was defeated in 1766, they generally accepted British sovereignty