The real innovation from Ford was the assembly line. It turned what had previously been a very manual process into something that could produce a complex device at industrial scale. Other folk may have had similar ideas previously, but Ford showed the world how it should be done.
The "automobile" itself was an iterative 'invention'. Many people were working on the same idea at the same time. There were many variations developed, using many different fuel sources.
The assembly line was extant during the American Civil War era and the expanding Industrial Revolution. Henry Ford
refined it for maximum efficiency and profitability.
The vast Yankee legions were not kitted out from cottage industries like too many of the Rebs were.