| The U.S. standard railroad gauge (distance between the rails) is four feet, eight and a half inches. That's an exceedingly odd number. Why was that gauge used? Because that's the way they built them in England, and English expatriates built the U.S. railroads. Why did the English people build them like that? Because the first rail lines were built by the same people who built the pre-railroad tramways, and that's the gauge they used. Why did 'they' use that gauge then? Because the people who built the tramways used the same jigs and tools that they used for building wagons, which used that wheel spacing. Why did the wagons use that odd wheel spacing? Well, if they tried to use any other spacing the wagons would break on some of the old, long-distance roads, because that's the spacing of the old wheel ruts. So who built these old rutted roads? The first long-distance roads in Europe were built by Imperial Rome for the benefit of its legions. The roads have been used ever since. | And the ruts? Roman war chariots made the initial ruts, which everyone else had to match for fear of destroying their wagons. Since the chariots were made for or by Imperial Rome, they were all alike in the matter of wheel spacing. Thus, the standard U.S. railroad gauge of four feet, eight and a half inches derives from the specification for an Imperial Roman army war chariot. |  | | 
