 In addition, infrastructure remains for what was one of the state's leading dairy farms during the first half of the 20th century.North Potomac did not get an identity of its own until 1989, when the United States Post Office allowed the use of the North Potomac name for what is mostly a collection of housing sub-divisions, farms, and wooded parks.The United States Census Bureau listed a North Potomac in 1970 but not 1980.