What is the main mountain chain that runs through eastern United states?

There are two major mountain chains that run through the eastern United States: the Appalachian Mountains and the Ouachita Mountains. The Appalachian Mountains are the more prominent of the two and stretch from Maine to Georgia, forming a natural boundary between the Atlantic Coastal Plain and the North American Interior. The Ouachita Mountains are a smaller range located in Arkansas and Oklahoma and are considered a continuation of the Appalachian Mountains.