The 1920's saw a period of rapid industrialisation, which made the decade to be correctly called the Roaring twenties. However, it is only the industrialists who benefited from the boom, with the majority of the working population conditions remaining poor. This was a fragile situation that led to the great depression as few money was circulating in the larger population. This has led to some conspiracy theorists attributing the blame of the great depression to the industrialists and bankers.
They migrated all over the North, Midwest, and the West, but I would say mainly the North?