The East Coast of the United States, also known as the Eastern Seaboard, the Atlantic Coast, and the Atlantic Seaboard, is the region encompassing the coastline where the Eastern United States meets the Atlantic Ocean. The Thirteen Colonies, which formed the United States in 1776 were located on this coast, and it has played an important role in the development of the United States. The region is generally understood to include the U.S. states that border the Atlantic Ocean: Connecticut, Delaware, Florida, Georgia, Maine, Maryland, Massachusetts, New Hampshire, New Jersey, New York, North Carolina, Rhode Island, South Carolina, and Virginia, as well as the federal capital of Washington, D.C., and non-coastline states: Pennsylvania, Vermont, and West Virginia.

Source: Wikipedia