[2] The county was organized January 2, 1833, and named for Meriwether Lewis, the explorer and Governor of the Louisiana Territory.

[4] Lewis County, located in the northeastern part of Missouri, across the Mississippi River from Illinois.

During the Civil War, the county became the base for rival pro-Confederate and pro-Union sympathizers; there was some violence but the Unionists prevailed.

[5] After the Civil War, the slaves were emancipated and the county's economy shifted towards commercial agriculture, with the production of corn, wheat and timber that were shipped through Canton, a port on the Mississippi River.

In the late 19th and early 20th century, farm youth moved into small towns, particularly in the western part of the county.

Mark Twain lived in the county briefly and was inspired by the natural beauty of the river region for his writing.

Chris Flanagan was appointed to the position of County Clerk by Governor Jay Nixon.

Senator Hillary Clinton (D-New York) received more votes, a total of 619, than any candidate from either party in Lewis County during the 2008 presidential primary.