Charlestown became a city in 1848 and was annexed by Boston on January 5, 1874. With that, it also switched from Middlesex County, to which it had belonged since 1643, to Suffolk County. 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. A mix of yuppie and upper-middle-class gentrification has influenced much of the area, as it has in many of Boston's neighborhoods, but Charlestown still maintains a strong Irish-American population and "Townie" identity.