John is correct, there were amazing industrial accomplishments during WWII from new fighters to Liberity ships, to repair of carriers, to munitions and arms production and many others.
Amazing accomplishments always have a foundation that were laid long before. ECs accomplishments are founded in an extensive steel industry, an extensive and healthy machine tool industry that only can exist in conjunction with a broader industry of heavy manufacturing, and lots of other industrial capability that made these accomplishments possible.
As critical to these successes was the existance of the human capital in terms of skilled workers, engineers, designers and managers with lots of industrial experience. In 1940/1941 the US had the infrastructure to move to high rate production.
Very different world now. The US, and increasingly the western world has lost much/most of the industrial capability from even 30 years ago. We had the capability because we built lots of things 15,800 P-51s, 12,600 P-47s, etc. all in 4 or 5 years. Today we are building 190 F-22s and they are being produced with a maximum rate of 20/year. It also took 12 years from the development contract to the first production delivery. We will spend 8 years producing 190 aircraft!!!
Why??? First, the aircraft is incrediably more complicated and capable than the P-51 and a generation plus beyond anything that is operational today, but it still shouldn’ take 12 years to develop and $34 Billion to produce. The truth is that the stack of requirements (small business, buy american, minority business, veteran owned business, Alaskan Indian owned business, cost accounting standards, certified cost & pricing data, use of american merchant vessels, acquisition reform, acquisition workforce management, environmental protection & impact, etc, etc, etc) that have nothing to do with developing an aircraft but are legal requirements imposed by public law passed by Congerss is taller than I am. Similarly, the pace of develop and production is a function of the budget process that constrains development and production rates, and drives costs, is controlled by a whole seperate set of laws providing constraints and oversight and reporting are a stack even taller!!! All of these requirements are important to someone for some reason, and some are added by DOD to make sure we comply with public law of to satisfy somebody at the policy level of government.
This is not a uniquely US problem, ask anyone in Europe and they will tell you a similar story.
The amazing thing is that the dedicated people at the bottom get anything done, ever.
Still, it gets more difficult each year as more laws are passed making the process increasingly complex. We are an Air Force with 20 first line bombers (B-2 which enteres service 15 years ago) out of the original production plan for 132 aircraft, and 190 first line fighters (F-22 which entered service 5 years ago) out of the original plan for 750.
The Army and the Navy has similar stories. Glad it isn’t my problem to solve.