Maryland is a state located in the Mid Atlantic region of the United States, bordering Virginia and West Virginia to the south and west, Pennsylvania to the north, and Delaware to the east. Historically it was part of the Chesapeake Colonies where planters cultivated tobacco as a cash crop dependent on slave labor.[4][5] It is comparable in size to the European country of Belgium.[6] According to the U.S. Census Bureau, Maryland has the highest median household income of any state at $68,080 in 2007, overtaking New Jersey in 2006. It was the seventh state to ratify the United States Constitution and bears two nicknames, the Old Line State and the Free State. Its history as a border state has led it to exhibit characteristics of both the Northern and Southern regions of the United States. Generally, the rural Western,[citation needed] Southern and Eastern Shore regions of Maryland reflect a Southern culture,[7] while densely-populated Central Maryland — radiating outward from Baltimore City and the Washington Beltway — exhibit characteristics of the Northeast.