[1] Both the county and its seat are named after Ulysses Grant, the 18th President of the United States.

The new counties were Decatur, Rawlins, Cheyenne, Sheridan, Thomas, Sherman, Lane, Buffalo, Foote, Meade, Scott, Sequoyah, Arapahoe, Seward, Wichita, Kearny, Greeley, Hamilton, Stanton, Kansas, Stevens, and Grant.

[4] In 1883, Kearny, Sequoyah, Arapahoe, Kansas, Stevens, Meade, Clark and Grant counties disappeared.

[3] In the 1930s, the prosperity of the area was severely affected by its location within the Dust Bowl.

This catastrophe intensified the economic impact of the Great Depression in the region.

21.00% of all households were made up of individuals, and 8.20% had someone living alone who was 65 years of age or older.

Michael Dukakis (as of 2024) is the last Democrat to win more than a quarter of the county's vote.

Grant 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% food sales requirement.