Union Pacific Railroad (or legally Union Pacific Railroad Company and simply Union Pacific) is a freight hauling railroad that operates 8,500 locomotives over 32,100 route-miles in 23 states west of Chicago and New Orleans. The Union Pacific Railroad system is the second largest in the United States after the BNSF Railway and is one of the world's largest transportation companies. The Union Pacific Railroad is the principal operating company of the Union Pacific Corporation (); both are headquartered in Omaha, Nebraska.
The Union Pacific legacy began in 1862 with the original company, called the Union Pacific Rail Road, which was part of the First Transcontinental Railroad project, later known as the Overland Route. The railroad would subsequently be reorganized thrice: as the Union Pacific Railway (which absorbed the original in 1880), as the Union Pacific "Railroad" (which absorbed the Union Pacific Railway in 1897), and finally as a renamed Southern Pacific Transportation Company (which merged with Union Pacific in 1998).