Charlestown is the oldest neighborhood in Boston, Massachusetts, United States. Originally called Mishawum by the Native Americans, 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 the first capital of the Massachusetts Bay Colony; it was a town in Middlesex County when the colony was partitioned on May 10, 1643. Charlestown became a city in 1848 and was annexed by Boston into Suffolk County on January 5, 1874. Most county functions have been assumed by Boston since the 1990s. 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.