The Economist magazine reports that more whites have moved away from the South than blacks, but that the white people carried their Southern politics with them. It says:

After America's civil war, millions of black Americans left the country’s southern states. Many were newly freed from slavery. They sought, and often found, better and safer lives, in manufacturing centres such as Detroit and New York. Known as the country’s “Great Migration”, this flow of people transformed the culture and economies of the places where migrants arrived. It also gave politics in northern cities an enduring push left.

But this was not the only great migration. Between 1900 and 1940, roughly 5m southern whites left former Confederate states and neighbouring Oklahoma.

The white migrants carried their convictions with them. Surveys conducted in the 1960s show that compared with white people born in the north, they were more often evangelical Christians, and tended to favour racial segregation and oppose government programmes to help black Americans. They were also more likely to set up churches and to work in newspapers and radio, which helped them share their views with their neighbours.