[2] The county was formed in 1857, and was named for the Cedar tree groves in the area.

[3][4][5] In the Nebraska license plate system, Cedar County is represented by the prefix 13 (it had the 13th-largest number of vehicles registered in the county when the license plate system was established in 1922).

[6] As of the 2000 United States Census[18] there were 9,615 people, 3,623 households, and 2,565 families in the county.

27.00% of all households were made up of individuals, and 15.70% had someone living alone who was 65 years of age or older.

In only one national election since 1936 has the county selected the Democratic Party candidate (as of 2024).