 Although most of California's railroads started off as short line railroads the period from 1860 to 1903 saw a series of railroad mergers and acquisitions that led to the creation of four major inter-state railroads servicing the state (the Southern Pacific Railroad, Union Pacific Railroad, Santa Fe Railroad and Western Pacific Railroad).Each of these railroads controlled one (and Southern Pacific controlled two) of the transcontinental railroads which linked California with states farther East.The railroads moved freight and passengers in large quantities and allowed the state's economy and population to expand rapidly during the late 19th and early 20th centuries.