"Old Dominion" became the tenth British colony to ratify the U.S. Constitution on June 25, 1788. The birthplace of a whopping eight of 44 U.S. Presidents, the Commonwealth is generally considered the northernmost of the Southern States. The Potomac River forms the Commonwealth's northern border, and the Chesapeake Bay and Atlantic Ocean lie to the east. The Appalachian Mountains dominate the Commonwealth's western landscape. Bordering the Commonwealth to the south is North Carolina, while Tennessee lies to the southwest, Kentucky and West Virginia to the west, and Maryland to the north. The Northern Virginia region, which includes Alexandria and Arlington, makes up part of the suburbs of Washington, D.C. The Hampton Roads region in the southeastern corner of the Commonwealth consists of such cities as Virginia Beach, Chesapeake, Hampton, Norfolk and Portsmouth. Virginia's capital city, Richmond, is near the middle of the Commonwealth; immediately to the south lies Petersburg, and in between Richmond and Washington, D.C. is Fredericksburg. Charlottesville is one of the cities representing the transition between the Piedmont Plateau region and the Appalachians. Winchester, Harrisonburg and Roanoke are some of the Commonwealth's mountain cities. Martinsville, Danville and Lynchburg are situated to the south.