Union Pacific Railroad Heritage covers the history of this amazing railroad that was founded in 1862 and completed the United States first transcontinental railroad in 1869.
With the need to develop more powerful steam locomotives to handle the railroad's steep gradients, the Union Pacific Railroad designed the 4-12-2 locomotive, 4-6-6-4 Challenger which influenced development of the 4-8-8-4 Big Boy, followed by the 6,600-horsepower Centennial...