Princeton is a city in Mercer County, West Virginia, United States. The population was 7,652 at the 2000 census. It is part of the Bluefield, WV-VA micropolitan area which has a population of 111,586. It is the county seat of Mercer County. The town hosts the Princeton Rays baseball club of the Appalachian League.
In southern West Virginia, in the late 19th century, coal mining and transportation by the emerging technology of the railroads combined to form a new industry. Much of the region's bituminous coal was sent west to the Great Lakes, or east to the Baltimore and Ohio Railroad's coal piers at Baltimore, or to the world's greatest ice-free port of Hampton Roads in eastern Virginia.
The Chesapeake and Ohio Railway's coal piers were located at Newport News. Across the harbor, the Norfolk and Western Railway's coal piers were located on the Elizabeth River in Norfolk. The eastern-bound coal transported by the C&O and the N&W railroads was highly-valued for local use and for steam-powered ships, notably those of the U.S. Navy. Loaded into large ships called colliers, the West Virginia "smokeless coal" was sent in coast-wise shipping to the Northeastern U.S. points such as New York City and New England, as well as exported to other countries worldwide.