US Map / Regions / South

South US Map

Sixteen states and the District of Columbia, from Delaware Bay to the Rio Grande — the most populous of the four Census regions.

How many states are in the South?

Sixteen, plus the District of Columbia — the biggest of the four Census regions by population and the one whose definition people argue about most. It runs from the Delaware Bay to the Rio Grande and takes in three divisions: South Atlantic, East South Central, and West South Central. About 132 million people lived here in 2024, close to 39 percent of the national total.

Texas and Florida between them account for more than 40 percent of the region's population and are the second- and third-largest states in the country. At the other end, Delaware and West Virginia each hold under two million.

Why the Census South includes states most people don't

Three memberships surprise almost everyone. Maryland and Delaware are counted South because the Bureau's South Atlantic division was drawn along the Mason–Dixon Line, the pre-Civil-War boundary between free and slave states, and it has not moved since. Residents of Baltimore and Wilmington overwhelmingly say Mid-Atlantic, and the Northeast is where most informal maps put them. Oklahoma is the third surprise: statistically it is West South Central and therefore Southern, but it was Indian Territory until 1907, its panhandle runs west far enough to border New Mexico and Colorado, and its own residents split between calling it Southern, Midwestern, and Southwestern.

The Bureau's regions were fixed in the early twentieth century for continuity of statistics, not for cultural accuracy, and that is the whole answer. Everyday usage runs on different lines: the "Deep South" is roughly Alabama, Georgia, Louisiana, Mississippi, and South Carolina; the "Upper South" is Virginia, North Carolina, Tennessee, and Kentucky; and the Southwest takes Texas away from the South entirely and hands it to Arizona and New Mexico. The regions hub lays the official version out in one table.

The South's largest cities

Four of the region's five biggest cities are in Texas: Houston, San Antonio, Dallas, and Fort Worth, with Austin just behind. Outside Texas the leaders are Jacksonville, the largest city by land area in the contiguous states, and Charlotte, the banking center of the Carolinas. Nashville, Memphis, Louisville, Oklahoma City, Baltimore, Atlanta, and Miami round out the list, and Washington sits inside the region as the District of Columbia. Full rankings are on the cities map.

Geography from the Appalachians to the Rio Grande

The southern half of the Appalachian Mountains crosses West Virginia, Virginia, Kentucky, the Carolinas, Tennessee, and northern Alabama, peaking in the Great Smoky Mountains on the North Carolina–Tennessee line; Mount Mitchell in North Carolina, 6,684 feet, is the highest point in the eastern United States. East and south of the mountains the land falls away across the Piedmont to the coastal plain and the Atlantic coast, then wraps west along the Gulf coast through Florida, Alabama, Mississippi, Louisiana, and Texas.

The Mississippi River runs down the middle of the region and forms the borders of Tennessee, Mississippi, Arkansas, and Louisiana; the Ohio River makes the northern edge of Kentucky and West Virginia; the Tennessee and Arkansas rivers drain the interior; and the Rio Grande forms the entire Texas–Mexico border. The Ozarks straddle Arkansas and Oklahoma.

The South's three Census divisions

• South Atlantic (8 states + DC)
• East South Central (4 states)
• West South Central (4 states)

The other three regions

North of the Ohio River is the Midwest, up the coast is the Northeast, and past the Texas panhandle is the West. The South map quiz uses this same sixteen-state list, so it is a fair check on whether the Census definition has sunk in.