Union Station, Portland, Oregon, circa 1900

The Union Pacific Railroad (reporting mark UP) (or 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 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. Two more Union Pacific railroads were formed after that, the Union Pacific Railway (the second company) which absorbed the original company in 1880 and the Union Pacific "Railroad" (the third company) which absorbed the Union Pacific Railway in 1897-1898. The third incarnation of the Union Pacific Railroad which operated from 1897 to 1998 is referred to as Mark I and it makes up the bulk of the Union Pacific history.