Originally called New Pennacook Plantation, the township was granted in 1779 to Timothy Walker, Jr. and associates of Concord, New Hampshire.

[3] Located in the foothills of the White Mountains, Rumford is the site of Pennacook Falls, called by historian George J. Varney "the grandest cataract in New England," where the Androscoggin River drops 177 feet (54 m) over solid granite.

Sawmills and gristmills were built to harness water power from the falls, although Rumford would remain primarily agricultural during its first 100 years.

[5] The first paper mill began operation in 1893, drawing an infusion of people and money into the sleepy community of about 200 residents.

[6] Much of the mill town was built in the spurt of prosperity between approximately 1890 and 1920, and Rumford retains significant Victorian and Edwardian architecture.

Wishing to avoid the stacked slums endemic at Lowell and Lawrence, Massachusetts, Hugh Chisholm commissioned Cass Gilbert in 1900 to plan a 30-acre (12 ha) site in his company town, instructing the prominent architect that "We will build of brick and stone and slate, and we will provide not merely for a house, but for comfort, elegance and social gratification.

"[7] Named after the seat of Clan Chisholm at Strathglass Carries, Scotland, Gilbert in 1901 produced 5 different designs for 51 duplexes.

The same year, Chisholm founded The Rumford Realty Company to build the oval-shaped development, its entrance marked by an imposing granite gateway.

With attractive lawns and broad, tree-lined streets, all maintenance was provided by the Oxford Paper Company.

In 1948 with the dissolution of the Rumford Realty Company, the existing duplex buildings were first offered for sale to the tenant of the two with the longest residency.

[8] Founded in 1961, under the sponsorship of prominent residents Louis Thibodeau, Minerva Anderson and Jonathan Mackenzie, the society pledges to preserve the rich history of the western mill town and encourage community involvement among all.

In June 1941, the cabin cruiser "The Don" sunk off of Harpswell, Maine with 34 residents of Rumford on board.

The cause of the wreck was never determined but multiple theories abound as to the vessel's demise including it being sunk by a U-boat or an insurance scheme.