By 1860 the American rail network stretched across the eastern states and was owned by numerous competing railroad companies that used many different track gauges. Much of the early rail network used the narrower 4 ft 81/2 in., 4 ft 10 in. or 5 ft gauges. Newer railroads whose construction started between 1838–48 used broader 5 ft 4 in., 5 ft 6 in. or 6 ft gauges which left the overall network highly unstandardized. The average percentage of the entire network which could be reached on a single gauge from a number of key terminals without crossing to another was just 18 per cent in 1860. Each of the main track gauges originated from certain points and expanded as nearby railroads adopted the same gauge in order to be able to cross services and expand the local network. At first this posed no problem as the regional rail networks remained relatively independent from one another but as the countrywide network expanded there was a push for standardization.
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