(THE CONVERSATION) On July 7, 1919, a group of U.S. military members dedicated Zero Milestone – the point from which all road distances in the country would be measured – just south of the White House lawn in Washington, D.C. The next morning, they helped to define the future of the nation.

Instead of an exploratory rocket or deep-sea submarine, these explorers set out in 42 trucks, five passenger cars and an assortment of motorcycles, ambulances, tank trucks, mobile field kitchens, mobile repair shops and Signal Corps searchlight trucks. During the first three days of driving, they managed ju...