Boston is the capital and largest city of the Commonwealth of Massachusetts, and is one of the oldest cities in the United States. The largest city in New England, Boston is considered the economic and cultural center of the region, and is sometimes regarded as the unofficial "Capital of New England." Boston city proper had a 2007 estimated population of 608,352, making it the twenty-first largest in the country. Boston is also the anchor of a substantially larger metropolitan area called Greater Boston, home to 4.4 million people and the tenth-largest metropolitan area in the country. Greater Boston as a commuting region includes parts of Rhode Island, New Hampshire and Maine; it includes 7.4 million people, making it the fifth-largest Combined Statistical Area in the country.