Elmira, city, seat of Chemung County, southern New York, on the Chemung River; incorporated as a city 1864. It is a manufacturing, commercial, and transportation center; major products include motor-vehicle and aircraft parts, glass, tools, subway and rail cars, hydrants, valves, packaging materials, and iron and steel items. Elmira College (1855), the Elmira Correctional Facility (1876), the Arnot Art Museum, the National Soaring Museum (housing a collection of motorless aircraft), and the grave of American writer Mark Twain are here. Nearby is a monument to the American Revolution general John Sullivan, marking the site of the Battle of Newtown (1779). In the battle, U.S. troops under General Sullivan defeated British and Native American forces led by Sir John Johnson and the Mohawk chief Joseph Brant. The first permanent settlement here was established in 1790. Originally incorporated as the village of Newtown in 1815, the settlement was renamed Elmira in 1828. Its main economic growth began in the 1850s. During the American Civil War, a large camp for Confederate prisoners was here. In 1972 the city was damaged by river flooding.