UP Bourbonais Creek Bridge (St. Marys)

After the Pacific Railway Act of 1862, numerous railroads were charting routes from the Midwest to the Pacific using federal land grants.  The Leavenworth, Pawnee and Western Railroad was initially authorized by the Kansas Legislature in 1855, and changed the name to the Union Pacific Railway, Eastern Division (UP-ED) in 1863.  In 1864, the UP-ED began construction on a 40 mile railroad line, extending from Kansas City, Missouri westwards towards Denver.  The railroad reached Salina, Kansas by 1865, and an additional 97 miles to Fort Riley, Kansas opened in 1866.  In 1867, an additional 152 miles to Hays, Kansas would open to traffic, followed by an additional 116 miles to McAllaster, Colorado in 1869.  The UP-ED would be merged into the Kansas Pacific Railway (KP) in 1869.  The KP continued construction westwards, constructing an additional 234 miles to Denver, Colorado in 1870.  The KP was sold to the Union Pacific Railway in 1880.  The railroad would change its name to the Union Pacific Railroad in 1901.  The UP had constructed a vast network of railroads, extending from the Missouri River westwards.  This route served as a secondary mainline for the railroad, roughly paralleling the First Transcontinental Railroad, which was constructed north of this line in Nebraska.  Between 1901 and 1905, significant upgrades were made to this line, including realignments and new bridges, and a second track from Kansas City to Topeka was constructed in 1906.  Since the initial construction, little has changed with this line.  UP spent significant capital upgrading the route in the 1990s, although traffic has slowed considerably in the 2010s.  Today, UP operates the Kansas Subdivision between Kansas City and Menoken, the Salina Subdivision between Menoken and Salina, the Sharon Springs Subdivision between Salina and Sharon Springs, and the Limon Subdivision from Sharon Springs to Denver.