In 1848, President James Polk created Oregon Territory and appointed Joseph Lane as the first territorial governor a year later. In the early 1840s, most Americans lived south of the Columbia River. By 1849, only 304 people lived north of the river, but in the next year that number tripled as more and more settlers ventured northward. As they moved farther away from the territorial government, the settlers felt left out of governmental matters and decided to separate from Oregon. Delegates met at the Monticello Convention in 1852 to list reasons for the proposed separation, and Congress found little opposition to the bill. Washington Territory—named, of course, for George Washington—was created in 1853. The initial territory included much of present-day Idaho and Montana. In 1863, Idaho Territory was carved off the whole, followed by Montana Territory in 1864, giving the territories much the same boundaries that the states now occupy.
When Washington became a territory, its population was under 4,000 people; by 1880 it had grown to over 125,000 and was considered a serious candidate for statehood. Washington was admitted as the 42nd state in 1889, with Olympia [1] as its capital and a growing population of over 173,000. When the news was telegraphed to Washington officials in Olympia, they discovered one problem; the telegraph had been sent collect, and they could not read it until the cost was paid. Welcome to the United States!
Links:
[1] http://www.moon.com/destinations/washington/south-puget-sound/olympia