King is the most populous county in Washington. The county seat is Seattle. About two-thirds of the county's population lives in the city's suburbs. The county was originally named after William Rufus King who was Vice-President when the Washington Territory was created. On February 24, 1986, the King County Council passed Motion 6461 renaming King County to commemorate the Rev. Dr. Martin Luther King Jr. (1929-1968), the civil rights leader, rather than William Rufus de Vane King (1786-1853), the vice-president-elect for whom the county was named in 1852. The stated reason for the change was the revelation that "William Rufus DeVane King was a slave owner and a "gentle slave monger" according to John Quincy Adams."
King County borders Snohomish County to the north, Kitsap County to the west, Kittitas County to the east and Pierce County to the South.