Kind of half-right, half-wrong, on both counts. The cotton gin, for example, was a product of industry that expanded production in the slaveholding South.

The problem with your analogy is that cash crops tend to command higher margins than foodstuffs like those grown in California. Margins are very low in agriculture, and it's a lot of hard, backbreaking, thankless work. That's before factoring in losses from climate conditions, insects, malformed food that nobody will buy and has to be thrown away...

So it's no surprise that wages are pitiful and labor supply remains low or relegated to immigrants who find toiling in the California sunshine preferable to the dangers and destitution found south of the border.