Charlestown is the oldest neighborhood in Boston, Massachusetts, United States. At one time was called Charlton and Mishawum, it is located on a peninsula north of the Charles River, across from downtown Boston, and also adjoins the Mystic River and Boston Harbor. Charlestown was laid out in 1629 by engineer Thomas Graves, one of its early settlers. It was originally a separate town and the first capital of the Massachusetts Bay Colony; it became a city in 1848 and was annexed by Boston on January 5, 1874. While it has had a substantial Irish American population since the migration of Irish people during the Great Irish Famine of the 1840s, since the late 1980s the neighborhood has changed dramatically because of its proximity to downtown and its colonial architecture. However, it still maintains a strong Irish American population and identity.