Originally built in 1704 by Rowland Ellis, a Welsh Quaker, it was called Bryn Mawr, meaning high hill. The modern town of Bryn Mawr is named after the house, and the National Register of Historic Places has it listed under the original name.
It was originally designed as a T-shaped, two-story fieldstone dwelling with a gable roof. The original front section is approximately thirty-seven feet wide and twenty-two feet deep and the rear extension is approximately eighteen feet wide and twenty-three feet deep. A one-story brick kitchen was added to the end of the rear extension. The house was renovated in 1911 and major additions were made in 1926.[3]
The Harriton Association was started in 1962 by a group of people who were concerned that the house and its surrounding grounds, which were privately owned at the time, would be subdivided and developed. The creation of the group was spearheaded by W. Dallas “Bob” Saybolt, a Philadelphia furniture manufacturer (Saybolt & Cleland Inc.) who served as the first president of the Harriton Association. The association removed the 1926 additions and restored the house to look as it did when Charles Thomson lived there. Those renovations were completed in time for the 1976 United States Bicentennial.
The association operates Harriton House as a museum and cultural resource. Tours are given from Wednesday through Saturday, and special events are held at the house throughout the year.
^"PHMC Historical Markers". Historical Marker Database. Pennsylvania Historical & Museum Commission. Archived from the original on December 7, 2013. Retrieved December 30, 2013.