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

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.

31.40% of all households were made up of individuals, and 17.70% had someone living alone who was 65 years of age or older.

The county has generally voted for Republican candidates by a larger margin with each succeeding election.

Trego County was a prohibition, or "dry", county until the Kansas Constitution was amended in 1986 and voters approved the sale of alcoholic liquor by the individual drink with a 30 percent food sales requirement.

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