[3][4][5] The History of Holt County, Missouri from the Time of the Platte Purchase through 1916 and The History of Holt and Atchison Counties, Missouri (published 1882) are available online.

[6][7] The first Post Office in Holt County opened in 1839 and was located on Thorp's Creek near Oregon.

[11] As of the census[17] of 2000, there were 5,351 people, 2,237 households, and 1,503 families residing in the county.

The racial makeup of the county was 98.47% White, 0.11% Black or African American, 0.47% Native American, 0.07% Asian, 0.02% Pacific Islander, 0.11% from other races, and 0.75% from two or more races.

29.70% of all households were made up of individuals, and 16.70% had someone living alone who was 65 years of age or older.

The Republican Party predominantly controls politics at the local level in Holt County.

Senator and former First Lady Hillary Clinton (D-New York) received more votes, a total of 283, than any candidate from either party in Holt County during the 2008 presidential primary.