The United States at that time still depended upon the Railroads or Ocean transport for getting around the big big Nation. No real paved roads yet. Henry Fords success was greatly aided by cheap fuel and a booming economy. The automobile transport infrastructure came as a result of the inexpensive doable family or privately owned automobile.
Most Americans lived on the farm away from all the railroad connections. Lots of different things had to come together to enable Henry Ford's success. But what made it all work was the tremendous migration of Americans off the farm into the suburban populated areas. Thus the created need of the automobile. The rest as they say is just history.
In 1904 Iowa had 102,448 miles of road. Only Missouri and Texas had more miles of road. The problem was that only 1.62 percent of those roads were surfaced with gravel or other materials.
In 1913, Iowa was #6 in the nation in auto registration, despite have no paved roads between towns til 1918
69.4% of the State's population 2.2M lived outside of cities in 1914. After WWI, Iowa was ranked 4th in the Nation for amount of rail at 9,994 miles, with and additional 720 miles being electrified.
But auto sales kept going up.