McCook, Nebraska was established in 1882 and was named in honor of Alexander McDowell McCook, a Brigadier General in the Union Army during the American Civil War.
George W. Norris (July 11, 1861 – September 2, 1944) who held seats in the U.S. House of Representatives and Senate from 1903 to 1943, was a resident of McCook. Norris was the driving force behind the conversion of Nebraska's legislature to a unicameral system; in the Senate, he was a leading figure behind the creation of the Tennessee Valley Authority. His house in McCook is operated as a museum by the Nebraska State Historical Society, and is listed in the National Register of Historic Places. Main (north-south) street through central McCook has been named Norris Avenue.
Four governors of Nebraska made their homes in McCook: Ralph G. Brooks; Frank B. Morrison; Ben Nelson, who currently represents Nebraska in the U.S. Senate and who McCook's airport was recently renamed in his honor; and, Nebraska's current governor, Dave Heineman, made his home in McCook temporarily, attending East Ward Elementary School for a couple of years.