Phoenixville (fēˈnĭksvĭl) [key], borough (1990 pop. 15,066), Chester co., SE Pa., on the Schuylkill River; settled 1720, inc. 1849. Iron deposits in the region led to the early development of an iron industry and later (1886) to the manufacture of steel. Food processing and tool and die manufacture are important; other products include corrugated boxes, plastics, and adhesives. Phoenixville was the westernmost point in the state reached (1777) by the British during the Revolutionary War. Several 18th-century stone houses are there. Valley Forge is a few miles to the southeast.