Rahway, city, Union County, northeastern New Jersey, on the Rahway River; incorporated as a city 1858. It is a manufacturing center producing chemicals, pharmaceuticals, metal and rubber items, and electrical appliances. Settled about 1700 as part of Elizabethtown and subsequently known as Spanktown, it was the site of an American Revolution skirmish in 1777. The city's present name, derived from that of a local Native American leader, was adopted in the early 19th century. Population 26,723 (1980); 25,325 (1990); 26,500 (2000).