In the mid-1800’s, a young Quaker gentleman named Nathan Dunn was a Philadelphia businessman. Through a series of bad financial decisions, Mr. Dunn found himself facing bankruptcy and was excommunicated by the Quaker Meeting. He then went into the Import-Export business, amassing a small fortune in the process. In the era 1837-40, he had John Notman, a local architect, design and build a "cottage" for him on property that formerly was owned by a blacksmith. The Dunn property encompassed 24 acres of land. Although the centerpiece of the property was his one story "Chinese Cottage", the property also boasted a Carriage House. Nathan Dunn died in 1843 and his sister sold the cottage and property to Franklin Levis, a Mt. Holly attorney, who enlarged the home and renamed it "Dunmore". Sometime after the turn of the century, Levis sold the property to Mr. Johnson.
In the early 1940’s, the Johnson estate was purchased for use as a Regional Grammar School. The Sister Servants of the Immaculate Heart of Mary (Scranton) were contacted to staff the school. The second floor of the residence was turned into temporary classroom space, while the Sisters took up residence at a second home south of the property. The school was constructed in two phases and was originally named Mt. Holly Regional Catholic Grammar School. The name was later changed to Sacred Heart School. In 1956, the school auditorium was erected.