General George Crook was a distinguished Civil War officer. He lived at Fort Omaha as commander of the U.S. Army's Department of the Platte from 1875 to 1882 and again from 1886 to 1888. He moved into the Italianate style two-story residence, commonly known as the Crook House, following its completion in 1879.
Building one was originally the Fort Omaha water filtration plant, then a post exchange, then the firehouse, then an officer's quarters. Since the 1890s its been the telephone exchange building, too. https://northomahahistory.com/2015/10/07/a-history-of-fort-omaha/