[2] The county was formed in 1873, and was named for William Phelps (1808–1889), a steamboat captain and early settler.

[3][4][5][6] In the Nebraska license plate system, Phelps County is represented by the prefix 37 (it had the 37th-largest number of vehicles registered in the county when the license plate system was established in 1922).

Phelps County terrain consists of low rolling hills, mostly devoted to agriculture, sloping to the east, and dropping off toward the river basin along its northern boundary line.

[9] As of the 2000 United States Census,[23] there were 9,747 people, 3,844 households, and 2,683 families in the county.

In no national election since 1936 has the county selected the Democratic Party candidate (as of 2024).