In the early days of automobile production, everything was “local” and “simple.” The raw materials required for the car, such as steel or rubber may have come from other destinations, but the actual processing of those materials, and the eventual assembly were all done in the same plant.
Now, we live in a much more globalized industry. A car that is ultimately sold to a customer in New York or Chicago is no longer built strictly in Detroit. Materials used in assembly can come from all corners of the world. And one vehicle may have components made by suppliers in Mexico, Canada, or even China, which are then shipped to the United States, where the vehicle will ultimately be built.