Baltimore is an independent city and the largest city in the state of Maryland in the United States. Baltimore is located in central Maryland at the head of the tidal portion of the Patapsco River, an arm of the Chesapeake Bay. Baltimore is sometimes referred to as Baltimore City in order to distinguish it from surrounding Baltimore County. Founded in 1729, Baltimore is a major U.S. seaport and is situated closer to major Midwestern markets than any other major seaport on the East Coast. Baltimore's Inner Harbor was once the second leading port of entry for immigrants to the United States and a major manufacturing center. The harbor is now home to the Harborplace, a shopping and entertainment center, and the National Aquarium in Baltimore. After a decline in manufacturing industries, Baltimore shifted to a service sector-oriented economy. Johns Hopkins University and Johns Hopkins Hospital are now the city's largest employers. Despite some economic revitalization efforts, Baltimore still has many urban problems such as concentrated poverty, crime, and inadequate public education.
As of 2007, the population of Baltimore was 637,455. The Baltimore Metropolitan Area, which includes the city's surrounding suburbs, has approximately 2.6 million residents; the 20th largest in the country. Baltimore is also the largest city in the Baltimore-Washington Metropolitan Area of approximately 8.1 million residents.
The city is named after Lord Baltimore in the Irish House of Lords, the founding proprietor of the Maryland Colony. Baltimore himself took his title from a place in Bornacoola parish, County Leitrim and County Longford, Ireland. Baltimore is an anglicized form of the Irish Baile an Tí Mhóir, meaning "Town of the Big House", not to be confused with Baltimore, County Cork.