The Atlantic coastal plain

Coastal plain

A coastal plain is an area of flat, low-lying land adjacent to a seacoast and separated from the interior by other features. One of the world's longest coastal plains is located in eastern South America. The southwestern coastal plain of North America is notable for its species diversity...

has both low elevation and low relief, but it is also a relatively flat landform

Landform

A landform or physical feature in the earth sciences and geology sub-fields, comprises a geomorphological unit, and is largely defined by its surface form and location in the landscape, as part of the terrain, and as such, is typically an element of topography...

 extending 2200 miles (3,540.5 km) from the New York Bight

New York Bight

The New York Bight is a slight indentation along the Atlantic coast of the United States, extending northeasterly from Cape May Inlet in New Jersey to Montauk Point on the eastern tip of Long Island...

 southward to a Georgia/Florida section of the Eastern Continental Divide

Eastern Continental Divide

The Eastern Continental Divide, in conjunction with other continental divides of North America, demarcates two watersheds of the Atlantic Ocean: the Gulf of Mexico watershed and the Atlantic Seaboard watershed. Prior to 1760, the divide represented the boundary between British and French colonial...

, which demarcates the plain from the ACF River Basin

ACF River Basin

The ACF River Basin is the watershed of the Apalachicola/Chattahoochee/Flint River Basin, in the United States, that begins in northern Georgia and flows into the Gulf of Mexico at Apalachicola Bay, near Apalachicola, Florida...

 in the Gulf Coastal Plain

Gulf Coastal Plain

The Gulf Coastal Plain extends around the Gulf of Mexico in the Southern United States and eastern Mexico.The plain reaches from the western Florida Panhandle, the southwestern two thirds of Alabama, over most of Mississippi, some of western Tennessee and Kentucky, southwest Arkansas, the Florida...

 to the west. The coastal plain

Coastal plain

A coastal plain is an area of flat, low-lying land adjacent to a seacoast and separated from the interior by other features. One of the world's longest coastal plains is located in eastern South America. The southwestern coastal plain of North America is notable for its species diversity...

 is bordered on the west by the Piedmont plateau

Piedmont (United States)

The Piedmont is a plateau region located in the eastern United States between the Atlantic Coastal Plain and the main Appalachian Mountains, stretching from New Jersey in the north to central Alabama in the south. The Piedmont province is a physiographic province of the larger Appalachian division...

, to the east by the Western Atlantic coastline, and to the south by the Floridian province

United States physiographic region

The list of continental United States Physiographic regions identifies the 8 regions, 25 provinces, and 85 sections. The system dates to Nevin Fenneman's paper Physiographic Subdivision of the United States, published in 1917...

.

The area has an average elevation in less than 900 meters above sea level and extends some 50 to 100 kilometers inland from the ocean.