Westernport traces its early settlement back to the colonial period before the Revolutionary War. Trappers and hunters in this virgin territory came to trade at the trading post located with a few other log cabins near the mouth of George's Creek on the Potomac River. In the period after the war, most of the land that is now Westernport was owned by James Morrison and Adam Sigler. Shortly afterwards, Thomas Hammond acquired the west side of George's Creek, which is now Westernport Hill.

The growth of Westernport was relatively slow during the early 1800s due to lack of good transportation. In 1851, the arrival of the Baltimore & Ohio Railroad provided an economical means of shipping coal from the many mines that were being opened. More jobs were created, resulting in an increase in population and an increase in home building. Opening of the West Virginia Pulp and Paper Company nearby in Luke in 1889 was a further boost to Westernport's economy.

During the 20th century, underlying economic factors changed but the century ended with the town enjoying overall growth and prosperity and providing a favorable environment in which to live and raise families.