The above graphic shows the decline in manufacturing jobs in the US. This is only half the story. True, employment in this sector is decreasing, but our actual manufacturing output per person is INCREASING:
This is production domestically in the US, not including "off-shored" production. How can we have more output with fewer workers? The use of technology in just about all phases of production is the primary culprit. Have you ever watched an episode of "How It Is Made" on The Science Channel? View some of the clips at the site and look to see how many workers there are (relatively few) and at the technology/processes that are used to perform tasks that only a few years ago required many workers to do. The jobs lost in American manufacturing in many cases were good paying jobs that allowed for a middle-class level standard of living for millions of Americans.
Watch these two short videos and count the number of production workers...It won't take long.