Plymouth is a borough in Luzerne County , Pennsylvania , 4 miles (6 km) west of Wilkes Barre , on the Susquehanna River . It was settled in 1768 by the Susquehanna Company and was claimed by Connecticut based on the charter of that colony. The Pennamite-Yankee War was fought in the environs. It is situated in the rich hard coal fields of the State. Coal was first shipped in 1807 . In the past, the chief products of its industrial establishments included mining drilling machines, miners' squibs, hosiery, silk, lumber products, etc. In 1900 , 13,649 people lived in Plymouth, in 1910 , 16,996 stayed here; in 1920 , 16,500; and 15,507 people lived here in 1940 . The population was 6,507 at the 2000 census.