Linn County Courthouse is located at 109 South High Street, Linneus MO 64653; phone: 660-895-5387. The Historic 3rd County Courthouse is located at 108 North High Street.
The area of Missouri that is now Linn County was originally part of Chariton County, established after Missouri statehood in 1820. The land was unsettled by white people at the time, rich with wild game and black soil, and full of thick forests. The Sac And Fox, Pottawattamie, and Musquakie Native American tribes were the primary inhabitants, as well as the occasional white hunter/trapper.
The first settlers to arrive in the area were white hunters from the Fayette area. James Pendleton and Joseph Newton were so beguiled by the temptations of the area that they returned a year later in 1831, with their wives and children. They settled in Section 14, Township 58, Range 21, which is today the Locust Creek Township. At the time, the area was nicknamed Locust Creek County. By 1833, there were 10 families in the area. The early settlers and resident Native Americans lived harmoniously together. There was some fear in the white settlers at the outbreak of the Black Hawk war in Illinois in 1833.
Although the war posed little or no threat to the residents of Locust Creek County, the area was evacuated nonetheless. When Black Hawk, the chief of the Iowa tribe and the leader of the war, was captured, the settlers moved back home and the area began to develop rapidly. By 1837, a thriving community was emerging and the petition to make the Locust Creek community a county was passed. On January 6, 1837, Linn County was approved. The county was named for Missouri U.S. Senator Lewis F. Linn who served his congressional term from 1833 to 1843 and died later in 1843.