William "Billy" Crooks (June 20, 1832 – December 17, 1907) was a Colonel during the American Civil War, member of the Minnesota House of Representatives, U.S. Military Academy graduate, and a veteran railroader. He led the 6th Regiment Minnesota Volunteer Infantry from August 1862 to October 1864, mainly contending against the Sioux. Crooks built the first rail line in the State of Minnesota, the St. Paul & Pacific. His first locomotive he named for himself the William Crooks 4-4-0 and began its operation in 1861. His operation was taken over by James J. Hill. The William Crooks would become the first locomotive of Hill's Great Northern Railroad.