former American railroad founded to build the first rail line west of the Mississippi River. Ground was broken in 1851 and the first section of track completed in 1852. It was the first railroad to serve Kansas City, Missouri, reached in 1865, after construction was interrupted by the American Civil War.

In 1872 the line was reorganized as the Missouri Pacific Railway, and in 1879 it came under the control of New York financier Jay Gould (Gould, Jay), who developed a system extending through Colorado, Nebraska, Arkansas, Texas, and Louisiana. In 1917 the line was merged with the St. Louis, Iron Mountain and Southern Railway Company and reorganized as the Missouri Pacific Railroad. Later it acquired other lines in the Gulf area and in Texas, extending its operating area to several Midwestern and Southwestern states.

The line's passenger operations were turned over to the National Railroad Passenger Corporation ( Amtrak) in 1971. In 1982 the Missouri Pacific merged with the Union Pacific (Union Pacific Railroad Company) and Western Pacific Railroad companies to form the Union Pacific System, under the holding company Union Pacific Corporation. Missouri Pacific, however, maintained its own corporate and commercial identity until 1997, when it fully merged with Union Pacific.