Thank you. I keep seeing this Agriculture jobs reference. But, no one mentions that (most of) those people left by their own will. Not because they were pushed out. My own family used to have a farm. All the boys left to go work in mills when they became of age.
I looked for a couple minutes and didn't find it conveniently already done, but it would be interesting to see a breakdown of the US work force from 1850, showing the percentage working in agriculture (including slavery pre Civil War) and the percentage of agriculture workers that were immigrants.
If there is a high proportion of immigrants working in agriculture it blows the whole theory into the sky, as that would be people answering demand for labor at pretty high personal cost, the opposite of incumbents getting pushed out.
This has the current info and some historic info (but not a convenient table!) for California, spread out all over the writing, the percentage of immigrants depends on the crop, for crops that require manual picking the vast majority of the workers are immigrants (everyone except the person in charge most of the time), 5% (800000/16000000) of the workers in California are temporary farm workers.
http://migration.ucdavis.edu/cf/more.php?id=174
I have seen a lot of movement back to agriculture. Friends of mine, many college educated, are working for farms or starting their own farms. Land is available and they seem to be doing pretty well.
