Baltimore is the most populous city in the U.S. state of Maryland. With a population of 585,708 at the 2020 census, it is the 30th-most populous city in the United States. Baltimore was designated an independent city by the Constitution of Maryland in 1851, and today it is the most populous independent city in the nation. As of the 2020 census, the population of the Baltimore metropolitan area was estimated to be 2,838,327, making it the 20th-largest metropolitan area in the country. When combined with the larger Washington, D.C. metropolitan area, the Washington–Baltimore combined statistical area (CSA) has a 2020 U.S. census population of 9,973,383, the third-largest in the country.