Sewell is an unincorporated community located within Mantua Township in Gloucester County, New Jersey, United States. Sewell also refers to part of Washington Township. It is named for United States Senator William Joyce Sewell. Sewell is notable for containing the Inversand marl pit, the last remaining, operational greensand mine in the world. The location has become renowned for its paleontology and is similar to many of the sites studied by early paleontologists, particularly Edward Drinker Cope. It is also home to the oldest bar in New Jersey, the Barnsboro Inn. Sewell also hosts Rowan College at Gloucester County and the Gloucester County Institute of Technology. The community is a planned stop on the Glassboro–Camden Line, an 18-mile (28.97 km) diesel multiple unit (DMU) light rail system projected for completion in 2019.