Territorial Timeline
King, Jefferson and Pierce counties created by the Oregon Territorial Legislature
Since Thurston County was seen to be too large, – its boundaries extended from the northern boundaries of Pacific and Lewis Counties, north to the Canadian border, east to the Cascades, and west to the Pacific Ocean – the Oregon Territorial Legislature created four new counties during the 1852-53 session.
King County was established on December 22, 1852 with its county seat established at Seattle. It was named after William Rufus De Vane King, acting vice president under President Millard Fillmore, who had succeeded to the presidency upon the death of President Zachary Taylor. When Fillmore became president, King was named vice president, but King died before he could formally take office.
Jefferson County was created on December 22, 1852 and named in honor of President Thomas Jefferson.
Pierce County was created by the Oregon Territorial Legislature on December 22, 1852 and named in honor of Franklin Pierce who had just been elected President of the United States.
Island County was created by the Oregon Territorial Legislature on January 6, 1853. It was named for the many islands within its boundaries and is the only county in the United States named “Island.” The bill creating the county would have passed earlier, but there was much discussion in the legislature about its name. Amendments to name it Atchison, Calhoun and Webster were introduced, discussed and defeated.