The history of Anoka County starts in 1849 when the Minnesota territorial legislature organized the counties of Washington, Ramsey and Benton. What is now Anoka County was embraced in both Ramsey and Benton Counties because the Rum River was the dividing line between the two counties.As early as 1850, fur traders began to settle on the Rum River in the area now known as Ramsey. As more settlers came into the area, this thriving community was given the name Anoka. The name originated from the Indian language, meaning "on both sides."​ In 1856, Sherburne County was detached from Benton County. That territory, lying east of Sherburne County and west of the Rum River, was also detached to become a part of Ramsey County. By an act of the legislature, Anoka County was formed from Ramsey County on May 23, 1857. The original eight townships included: Anoka, Watertown (Ramsey), Round Lake (Andover), Bethel, Columbus, St. Francis, Oak Grove and Centerville.The original boundaries of Anoka County were the same as today except for a small portion of the southeastern tip of the county along the Mississippi River at the south. This strip was a tiny county created from Ramsey County the same day Anoka County was created. This tiny county was given the name of Manomin and occupied only about one-third of a congressional township. It functioned as an organized county until abolished and attached to Anoka County by constitutional amendment November 2, 1869. As an organized township of Anoka County, Manomin kept this name until it was changed to Fridley in 1879. In 1877, the Board of County Commissioners voted to build a courthouse on the present site of the County Courthouse. The building was completed in January 1878. Starting in 1955 various construction projects have transformed the original Courthouse into the Anoka County Government Center and numerous other buildings including: Libraries, Highway Maintenance, Parks Administration and Human Services facilities.