Baltimore ( BAWL-tim-or, locally: ) is the most populous city in the U.S. state of Maryland, as well as the 30th most populous city in the United States, with an estimated population of 593,490 in 2019. Baltimore is the largest independent city in the country and was designated as such by the Constitution of Maryland in 1851. As of 2017, the population of the Baltimore metropolitan area was estimated to be just under 2.802 million, making it the 21st largest metropolitan area in the country. Baltimore is located about 40 miles (64 km) northeast of Washington, D.C., making it a principal city in the Washington–Baltimore combined statistical area (CSA), the fourth-largest CSA in the nation, with a calculated 2018 population of 9,797,063.
Prior to European colonization, the Baltimore region was home to the Susquehannock Native Americans. British colonists established the Port of Baltimore in 1706 to support the tobacco trade, and established the Town of Baltimore in 1729. The Battle of Baltimore was a pivotal engagement during the War of 1812, culminating in the bombardment of Fort McHenry, during which Francis Scott Key wrote a poem that would become "The Star-Spangled Banner", which was eventually designated as the American national anthem in 1931. During the Pratt Street Riot of 1861, the city was the site of some of the earliest violence associated with the American Civil War.
The Baltimore and Ohio Railroad, the oldest railroad in the United States, was built in 1830 and cemented Baltimore's status as a major transportation hub, giving producers in the Midwest and Appalachia access to the city's port. Baltimore's Inner Harbor was once the second leading port of entry for immigrants to the United States. In addition, Baltimore was a major manufacturing center.