On This Date in Minnesota History: January 9

January 9, 1840 – On this date, the new  “County of St. Croix [was] created by the Territorial Legislature of Wisconsin, incorporating today's Washington County [of Minnesota]. ‘Dakotah,’ Joseph Brown's settlement, [was] chosen as the county seat.”
http://projects.wchsmn.org/reference/events/st-croix-county/