The Eastern United States or the American East, is today defined by some as the states east of the Mississippi River, and is traditionally divided by the Ohio River and Appalachian Mountains into the South, the Old Northwest and the Northeast. The first two tiers of states west of the Mississippi have traditionally been considered part of the West, but can be amalgamated with states of the Old Northwest into what the Census Bureau defines as the Midwestern United States. It has been considered part of the Eastern United States in regional models that exclude a Central region.
As of 2011, the estimated population of the 26 states east of the Mississippi (not including the small portions of Minnesota and Louisiana that are east of the river) plus Washington, D.C. totals 179,948,346 out of 308,745,358 in the whole nation (excluding the territory of Puerto Rico), or 58.28% of the U.S. population.
The Southern United States constitutes a large region in the south-eastern and south-central United States. Because of the region's unique cultural and historic heritage, including Native Americans; early European settlements of English, Scots-Irish, Scottish and German heritage ; importation of hundreds of thousands of enslaved Africans; growth of a large proportion of African Americans in the population, reliance on slave labor, and legacy of the Confederacy after the American Civil War, the South developed its own customs, literature, musical styles, and varied cuisines, that have profoundly shaped traditional American culture.The South's culture is deeply rooted in the American Civil War.