Whether any significant jobs actually moved from pre-civil war North to South or if they mostly grew up where the labor market was most appropriate for them is irrelevant.It was the central "relevant" point in your previous post, now it is irrelevant. So which is it?
It’s still much like today’s America/Asia labor gap, with cheap labor in one area, expensive in another and no tariffs in-between. Yet the North thrived. How could that be?
The North did not have expensive labor. Every educated person knows that. It had a huge population of immigrants from Ireland and Eastern Europe crammed into slums in the major cities of the North. The North had a manufacturing economy, the South an agricultural economy. Today, Asia has a manufacturing economy, the primary exports of the US are agricultural products.
Northern labor pre civil war was more costly then slave labor. And post civil war the southern economy changed and became prosperious because it was forced to use and compete with high cost labor. This is what the free traders do not understand, an economy is built bottom up by creating a marget that can afford to consume the products that the economy produces. Henery Ford understood this which is why he became rich by paying his workers a high wage. "I want my workers to be able to buy my cars" H. Ford.