Morrill County, Nebraska: History
The Battle of Mud Springs and the Battle of Rush Creek between the US Army and Cheyenne, Lakota Sioux, and Arapaho occurred in 1865 within what would become Morrill County.
On November 3, 1908, voters in Cheyenne County passed a measure calling for the division of that county. Accordingly, the Nebraska State Legislature passed an act providing for the division of Cheyenne County, the line of division running east–west, south of the town of Bridgeport. The northern portion so divided was to be called Morrill County. In December of that year, another election determined Bridgeport to be the seat of the new county, and the new county's officials were determined. The county was named for Charles Henry Morrill, a president of the Lincoln Land Company.