Baltimore is the largest city in the U.S. state of Maryland, and the 29th-most populous city in the country. It was established by the Constitution of Maryland and is not part of any county; thus, it is the largest independent city in the United States, with a population of 621,849 as of 2015. As of 2016, the population of the Baltimore metropolitan area was estimated to be just under 2.8 million making it the 21st largest metropolitan area in the country.
Founded in 1729, Baltimore is the second-largest seaport in the Mid-Atlantic. Baltimore's Inner Harbor was once the second leading port of entry for immigrants to the United States and a major manufacturing center. After a decline in major manufacturing, industrialization and rail transportation, Baltimore shifted to a service-oriented economy, with the Johns Hopkins Hospital (founded 1889), and Johns Hopkins University (founded 1876), now the city's top two employers.