Freakonomics fearlessly explains everything. It's tempting to say that the South commemorates the War more than the North because the South is where the war was fought. But I suspect there's more to the story than that, particularly when you consider that many of those who are most eager to commemorate it are also eager to rewrite the history of the War.
Those consequences are most apparent in the economic inversion that took place following the war. The parts of the South that were generally the richest in 1860 are today its poorest. These were the areas with the highest concentration of plantations: a swath of land stretching from coastal South Carolina down through Georgia, and west into Alabama, Mississippi, and Louisiana. Today, this region is home to some of the poorest counties in America, with high rates of unemployment, low-skilled labor, and other social ills like obesity and a lack of education.
From the June 7 blog posting at "Freakonomics: the Hidden Side of Everything."