Henry Ford did not invent the assembly line. He combined existing pieces. Interchangeable parts came from the armories. Moving overhead trolleys came from Chicago meatpacking.
Ford said so himself in 1922. The idea “came in a general way from the overhead trolley that the Chicago packers use in dressing beef.” The packers took animals apart. Ford put cars together.
The first moving line ran at Highland Park in October 1913. A Model T that took 12 and a half hours to build soon took 93 minutes.