This video describes US economic growth as the product of a long steady political-economic process:
The video omits the argument wherein the US Civil War accelerated industrial growth in the North and disrupted economic growth in the South. The prosperous middle class in the United States emerged primarily after World War II. For a few decades the US transportation fleet ran primarily on legacy MIL-SPEC parts and WWII era industrial standardization. We call that sort of technology Industry Standards, Public Domain, and/or Open Source. The US also has a long history of government-led political efforts to reduce barriers to trade in interstate commerce. The governments began to establish the Uniform Commercial Code (UCC) in the 1950s.
Joe