Henderson County, established back in the early 1840s, was named after the Henderson River sharing frontiers with Mercer, Warren, Hancock, and McDonough Counties in Illinois State along with Lee and Des Moine Counties in Iowa State. Some of the communities in this territory of 395 square miles of area are Bald Bluff, Carman, Gladstone, Lomax, and Media. The village of Oquawka with approximately 1540 residents serves as the county seat of this territory home of more than 8200 people and divided in nine cities, six unincorporated cities, and eleven townships.

Stephen Mathers is the Chief Judge of the Ninth Judicial Circuit.