Oregon's settlement may be conveniently dated from the expedition of Marcus Whitman in 1836. The few trappers and traders who had arrived in early days may be disregarded. Thus began the short-lived race between the United States and Great Britain to colonize the country and to have their claims to possession based on effective occupation. American immigration did not commence in earnest until 1842 or 1843, but continued steadily, until the discovery of gold in California diverted many to that territory.
Most of the early American settlers came from Missouri or Iowa, and represented therefore either the Southern or New England pioneer stock. In general it may be said that Oregon at that time was settled from the Mississippi Valley, and mainly by men who came as genuine settlers with their families, in striking contrast to the adventurers who invaded California.
Meanwhile, the British colonizers were coming from Canada, many of them French-Canadians, while the rest were mostly of Scotch ancestry. But the American population grew so much more rapidly that by 1846, when the Treaty was made defining the parallel of 49° as the boundary between the two nations, there were nearly 8000 American settlers in the Oregon territory as against about 1500 of British allegiance.
In 1860, of the 30,500 native immigrants in the State 40 per cent were of Southern birth. Nearly half of these were from Missouri, and a large part of the others from Kentucky or Tennessee. The remainder represented principally the New England stock which has always been considered to be the foundation of Oregon.
The actual permanent settlement of the Puget Sound country began in 1845, but progress for some years was slow. Scarcely had a start been made here when the gold rush turned everyone's attention to California. Following this came the Indian war of 1855 to 1856, and shortly afterward the Civil War upset all plans, leaving the few scattered inhabitants of the Puget Sound region in the midst of a wilderness, surrounded by hostile savages, and inevitably neglected by the government to which they naturally looked for attention.
Washington was separated from Oregon and established as an independent territory in 1853. The census found there only 3965 white persons, a small number to assume the responsibilities of a separate political existence. Walla Walla Valley was opened up in 1859, when the removal of a military interdict and a survey of public lands allowed a waiting population of some 2000 to rush in and spread over the whole of eastern Washington within a short time.