* Atlantic Slope Basin: This basin slopes eastward toward the Atlantic Ocean, draining into rivers like the Susquehanna, Delaware, Potomac, and James.

* Mississippi Basin: This vast basin encompasses the Mississippi River and its tributaries, draining westward towards the Gulf of Mexico.

The Appalachian Mountains act as a continental divide, separating the drainage patterns of the two basins. Rain falling on the eastern side of the Appalachians flows eastward to the Atlantic, while rain falling on the western side flows westward to the Mississippi River.