I would put the #2 panel likely around the 1910’s, when Ford’s five dollar day started pushing up wages across factory workers in the area. It wasn’t perfect, but it did bring a lot of people out of poverty.
There is an issue of relative versus absolute progress.
The 1910’s were the first time in American history where a single factory worker could sustain a household on one salary, including purchasing a car. It wasn’t a perfect system and included a lot of corporate paternalism, but it was far better than what came before.
And the issue of working in a factory in the 1970’s had less to do with the working conditions and more to do with having a job. It wasn’t like conditions in a factory got worse between the 1950’s and the 1970’s, but more that the factory might close altogether and destroy a local town’s economy.
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