The U.S. state of Washington has thirty-nine counties. The Provisional Government of Oregon established Vancouver and Lewis Counties in 1845 in unorganized Oregon Country, extending from the Columbia River north to 54°40′ north latitude. After the region was organized within the Oregon Territory with the current northern border of 49° north, Vancouver County was renamed Clarke, and six more counties were created out of Lewis County before the organization of Washington Territory in 1853; twenty-eight were formed during Washington's territorial period, two of which only existed briefly. The final five were established in the 22 years after Washington was admitted to the Union as the 42nd state in 1889. King County, home to the state's largest city, Seattle, holds 30 percent of Washington's population (2,252,782 residents of 7,614,893 in 2019), and has the highest population density, with more than 1,000 people per square mile (400/km2). Garfield County is both the least populated (2,225) and least densely populated (3.1/sq mi [1.2/km2]). (Full list...)