The first settlement in the Puget Sound area in the west of what is now Washington, was that of Fort Nisqually, a farm and trading post of the Hudson's Bay Company, in 1833. Washington's erstwhile founder, the black pioneer George Washington Bush and his caucasian wife, Isabella James Bush, from Missouri and Tennessee, respectively. They led four white families into the territory and settled New Market, now known as Tumwater, Washington, in 1846. They settled in Washington to avoid Oregon's racist settlement laws. After them, many more settlers, migrating overland along the Oregon trail, wandered north to settle in the Puget Sound area.
When the war came, Washington was still very much a new territory, but political inclinations to join the Union dated back to at least as early as 1852. One regiment of Union soldiers was raised in Washington, numbering 1521 men.
Many more men, both Union and Confederate migrated to Washington after the war.