There's all sorts of literature on the early American auto industry in industrial cities... Milwaukee, Kenosha, Racine, Toledo, Cleveland, Erie, and Buffalo all had early auto manufacturers by the 1890s.
All of those places had: extensive port and rail transportation networks for receiving raw materials, hundreds of machine shops, engine works, and boiler/stove works operating, and huge numbers of immigrant workers coming in... the ingredients necessary for large-scale manufacture of internal combustion engine autos.
In fact, from 1895 and 1899, 69 automobile manufacturers were established in the US...
ZERO were located in Detroit.
That is until Michigander Ransom Olds relocated his company from Lansing to Detroit 1900. He is as much responsible for the "Motor City" as Henry Ford is.
From early on, Olds subcontracted work out to Detroit's manufacturers to make the parts for his car.. which led to those subcontractors gaining expertise in auto production... which gave rise to those subcontractors creating their own companies, namely Cadillac, Hudson, Buick, Chevrolet, Lincoln, Dodge, and ultimately GM. This was early technical R&D at industry scale and other cities could not compete with the innovation network in Detroit. The money followed this innovation to Detroit, rather than going elsewhere. And then Henry Ford came in a and integrated all of it.
They are the reason why Detroit became the Motor City -- fellow Michiganders Ransom Olds and Henry Ford.
The auto industry has always been a topic of interest to me. Good academic read on it for those interested:
The Evolution of the U.S. Automobile Industry and
Detroit as Its Capital
http://ftp.zew.de/pub/zew-docs/entre...ip/klepper.pdf