Pulling levers and pushing buttons and shoveling coal into a furnace aren't that skilled, but factory workers used to make enough to have a modest home, two cars, mom at home, TV, Junior's sports equipment and Marianne's Piano Lessons with a two week vacay at the Gulf/Lake.
What happened is that a return to mass immigration and lack of immigration enforcement flooded the labor pool.
Also consider the entry of women en mass into the labor force. The economy adjusted somewhat to a two-income household.
Need help understanding the question? Apparently so. I used small words and typed very slowly so I don't know where to go from here to make it more comprehensible. .
Changes in real wages: