The name traces its origins to the Galveston, Harrisburg and San Antonio Railway, a Southern Pacific Railroad subsidiary which was known as the Sunset Route as early as 1874.[citation needed] The line was built by several different companies and largely consolidated under Southern Pacific. The first trains departed for through service between Los Angeles and New Orleans on February 5, 1883.[2]
Upon Southern Pacific Railroad's merger with Union Pacific in 1996, less than 25% of the route was double-tracked.[3] Efforts to expand double-trackage were ongoing as of the late 2000s and early 2010s,[4] with over 70% of the route having two tracks by 2012.[3]
The line is primarily used for freight by the Union Pacific. BNSF shares ownership of the Lafayette Subdivision.[5] By 2007, 45 trains daily were operating through Maricopa, Arizona.[4] The AmtrakSunset Limited operates three round-trips weekly over the entirety of the route with the Texas Eagle attached between San Antonio and Los Angeles.
