Boston is the capital and most populous city of the Commonwealth of Massachusetts in the United States, and the 21st most populous city in the United States. The city proper covers 49 square miles (127 km2) with an estimated population of 694,583 in 2018, also making it the most populous city in New England. Boston is the seat of Suffolk County as well, although the county government was disbanded on July 1, 1999. The city is the economic and cultural anchor of a substantially larger metropolitan area known as Greater Boston, a metropolitan statistical area (MSA) home to a census-estimated 4.8 million people in 2016 and ranking as the tenth-largest such area in the country. As a combined statistical area (CSA), this wider commuting region is home to some 8.2 million people, making it the sixth most populous in the United States.