1-153-171 - Ann Ronan Picture Library/Heritage-Images

Train crossing a wooden trestle bridge on the Union Pacific Railroad, near Sherman, Wyoming, USA, c1870. Incorporated by an Act of Congress in 1862, the Union Pacific Railroad was built to extend the American railway system westwards across the country to the Pacific. The first rails were laid in Omaha, Nebraska, and the line was completed when it joined the Central Pacific Railroad at Promontory, Utah in May 1869. The railway was instrumental in bringing about the economic development of the American West.