The Catholic Church in Mt. Holly was established sometime between 1845-48 by the Bishop of Newark. At the time, the Newark Diocese was the only Catholic Diocese in New Jersey.
 
In 1845, St. Paul’s in Burlington City was the first parish established in Burlington County. The parish in Mt. Holly, established as a Mission of St. Paul’s in 1848, was originally called St. Mary’s. The land was purchased from the Risdon family near the corner of Union St. and Mt. Holly Avenue and the church was built in 1852. It was a wooden structure measuring 25 feet by 65 feet.
 
As the parish grew, a larger house of worship was needed. In 1871, Father Thaddeus Hogan was assigned to Mt. Holly. He found a large congregation and a dilapidated church. Land for a new church was purchased from Joseph Bispham on North Washington St. and the construction of the new church was started as a Sunday project by members of the parish. The original plan included a bell tower on the northeast side. When the new St. Mary’s was dedicated in 1872, the older church building was cut in half and transported via wagons to its present location. With the addition of a stage and restrooms, the older structure became the Parish Hall. Over the years, it would also serve as an early school for the children of the parish.
 
The name of the church was officially changed to Sacred Heart in January, 1881.
In the late 1980’s, the pastor of Sacred Heart petitioned the Diocese to refurbish the Church on Washington St. The plans developed by the Diocese instead called for the construction of a new church on the property adjoining the Convent. This third church was dedicated in 1991 and is still in use
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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.