In May 1869, the U.S. railroad network unified when the Central Pacific and Union Pacific railroads came together in Promontory, Utah. ''The Transcontinental Railroad'' discusses this important milestone in the expansion of the United States and its impact on the nation, both positive and negative. This book tells how the east-west railroad played an integral role in opening western markets to residents of the eastern United States, but it also examines how the railroad led to the demise of many American Indian groups in the West.