These 11 cut-paper slides will take you through the early history of the Central Pacific and Southern Pacific Railroads. Though heralded as the great unifier of America, the transcontinental rail line was built far ahead of demand. While regional rail networks often proved profitable, the transcontinental railroad was initially a failure. The first three decades of the original Pacific Railroad and subsequent transcontinentals were fraught with financial troubles, internal corruption and fierce competition with cheaper, more established shipping routes. It wasn't until nearly 1900 that cross-country rail traffic became consistently profitable.