Not sure what the nature of your question is, but a few details about Ford early history [others can fill in as appropriate]. The first Ford Motor Company plant was in a rented building on Mack Ave. in Detroit. This is where the first Model A (1903) was made. The first Ford owned building was on Piquette Avenue - also in Detroit. It was built in 1904 and they moved to the new and very large Highland Park Assembly plant in 1910. The first Model T's were made at the Piquette plant, but Highland Park produced the next 15 million Model T's. Geographically, the city of Highland Park is completely surrounded by the city of Detroit. In 1927, production of the new Ford vehicle, the second Model A, was started at the huge Rouge facility in Dearborn. All of the Model A engines were produced at the Rouge engine plant and shipped to the other various assembly plants.
Why did Ford end up in Dearborn? Dearborn is still a suburb of Detroit and it is also the birthplace of Henry Ford. He grew up on a farm about a mile from Ford's current World Headquarters. Initially, Dearborn was "way out in the country" and Ford bought substantial parcels of property within the city limits as his company began to make money. His Fairlane Mansion was also located in Dearborn, so it was natural that the center of the company moved to this area.
Ford, like GM and Chrysler, has always been involved in the life and activities of Detroit. Although there are numerous suburb cities around Detroit, most people [and companies] identify themselves as being from Detroit and not from Dearborn, Ann Arbor, Westland, Novi, Troy, etc.