The States subsequently acquired California and other adjoining states during their war with Mexico in 1848, just before gold was discovered in the Sacramento valley.
The land between California and Alaska was held in joint possession between Great Britain and the States, and was known as the Oregon Territory.

Lewis and Clarke had explored the Columbia River, while Vancouver had much earlier examined the island which now bears his name, so that both countries appear to have some rights of discovery to the district.

At one time the inhabitants of the States were inclined to claim all the country as far as the Russian boundary 54.40 deg., and a war-cry arose "54.40 deg.

or fight;" but in 1846 the territory was divided by the 49th parallel, and at this date we may say the partition of America was complete, and all that remained to be known of it was the ice-bound northern coast, over which so much heroic enterprise has been displayed.
The history of geographical discovery in America is thus in large measure a history of conquest.

Men got to know both coast-line and interior while endeavouring either to trade or to settle where nature was propitious, or the country afforded mineral or vegetable wealth that could be easily transported.