A lot of American engineers, a good amount of Japanese and German engineers, too (those three completely dominate the field of automation and industrial robotics, like 98%). Most are manufactured by robotics. Go check out the ABB assembly lines and you'll see 98% of the work done by robotics, with technicians monitoring output screens.
Robots stack our pancakes, eliminating 3 dozen people with just 4 robots.
Robots pack furniture, eliminating thousands of workers and all chances of L&I disability claims.
Robots pick and sort matched components with speed beyond what a team of 20 people can do, with higher accuracy.
Here's a FANUC (an American company) with a massive 40 tool head, doing the job of 20 people, and lifting a 200 pound component at the end. Doing it with precision and repeatability and in a tenth the time of the human team.
Go to any large manufacturing company that used to employ tens or hundreds of thousands of people, and you'll find massive amounts of automation. Jobs are down because we're using fewer, smarter engineers to design automation systems, and then using those same automation systems to build more automation systems.
Many more jobs are lost to automation than overseas companies; in fact, even in China the big State employers are facing huge pressure from smaller, privately owned companies with robotics. Manufacturing jobs are gone because we simply do not need them any more. We've replaced those jobs with robots.
Excellent post. And the flip side of that is that even if protectionist measures increased the cost of domestically produced textiles (for example) the point where employers could pay textile workers even the minimum wage, most such textiles would be produced in highly automated factories providing only a fraction of the jobs of their predecessors, and most of those would be semi/ highly skilled jobs for which displaced American textile workers are not qualified.