On December 22, 1852, the Territorial Legislature of Oregon decided that Thurston County was far too large. The legislature divided it into 3 counties - King, Jefferson and Pierce County. The legislature also located the county seat at Steilacoom, this was mostly because it was the only town in Washington with its own jail. The following 40 years saw boom years and bust years, industries come and go, wars and depression, the population grow and the population shrink. In 1880, the county seat was moved to New Tacoma on Commendement Bay and in 1883, Tacoma City and New Tacoma merged to form Tacoma. By 1901 the region was recovered and strong and up through the war years, it thrived. From the 1950s until today, the county has grown and prospered with a population as of 2021 of approximately 925,708.