[3][4] The county originally had been named after William Cabell Rives,[5] who was then serving as a U.S.

However, Rives lost popularity in Missouri after he joined the Whig Party.

[6] As of the census[12] of 2000, there were 21,997 people, 9,133 households, and 6,246 families residing in the county.

27.70% of all households were made up of individuals, and 13.30% had someone living alone who was 65 years of age or older.

The Democratic Party historically controls politics at the local level in Henry County.