[1] The county was named for John Rooks, a private in Company I of the 11th Kansas Cavalry Regiment, who died at the Battle of Prairie Grove during the American Civil War.

[3] For many millennia, the Great Plains of North America was inhabited by nomadic Native Americans.

[5] In 1802, Spain returned most of the land to France, but keeping title to about 7,500 square miles.

In 1803, most of the land for modern day Kansas was acquired by the United States from France as part of the 828,000 square mile Louisiana Purchase for 2.83 cents per acre.

The county jail was built nearby from cottonwood logs strengthened by tons of iron.

The Rooks County Courthouse was added to the National Register of Historic Places in 2002.

The last Democrat to exceed a quarter of the county's vote was Michael Dukakis in 1988 during a major drought on the Great Plains.

[17] † means a community is designated a Census-Designated Place (CDP) by the United States Census Bureau.