All Philadelphia land west of the Schuylkill River was farmland and useless swamp in 1865. At that time, Saint Clement Parish was established to minister to the needs of the people who lived in that area. By 1890, the parish grew and a school was added. Southwest Philadelphia thrived and the swamps were filled with row houses. As the remote districts of the parish became more populated with Catholics, small chapels were built. As needed, these chapels became independent parishes. In 1919, one such chapel became St. Barnabas Church. A parish school was added in 1927. Throughout their histories, both parishes have been guided by Diocesan priests. The schools were staffed by the Sisters, Servants of the Immaculate Heart of Mary and lay teachers.
As industry grew and area people prospered, parishioners moved from their small city homes to the more spacious suburbs. Attendance at churches and schools dropped rapidly. Surrounding schools were closed and the two remaining schools, Saint Clement and Saint Barnabas, absorbed all students who still desired education in a Catholic school.
In June of 2004, Saint Clement Church and School closed as did Saint Barnabas School. An area school was established in the former Saint Barnabas School Building. The merged schools were renamed as one, and called Mary, Mother of Peace Area Catholic School. In July, 2014, St. Barnabas reclaimed the name “Saint Barnabas” as it joined the community of Independence Mission Schools (IMS). IMS represents a new and dynamic model for sustainable education, using the best practices in education and business to deliver a high-quality, cost-effective Catholic education to children and families of all faiths in underserved urban neighborhoods, through a new model of governance, funding, and accountability for the member schools.