St. Agnes was founded in 1867. The origin of the parish can be traced to the settlement of German Catholics in what was then Mifflin Township. Before 1867, these Catholics attended St. Peter in McKeesport. By 1867, enough Catholics had settled in the area to support a parish. On March 19, 1867, the parish was officially established. The next year work on a new church began and the completed building was dedicated on August 1, 1869. From 1869 until 1889, the basement of the church served as the parish school. For the first year and a half, the parish was a mission of St. Peter, but in October 1868, a resident pastor was appointed.
This church served the parish for a century. In 1969 an inspection of the church revealed that the building was no longer safe to use. On October 1, 1969, the decision was made to renovate the school audio-visual room and library as a temporary church. On October 5, 1969, the last Mass was celebrated at the original church. In November 1973, work began on a new church. The church was completed and dedicated on May 25, 1974. On June 5, 1974, the old church caught fire and was completely destroyed.
On October 11, 1992, new stained glass windows were installed in the church. Other than this change, the church as built in 1974, continues to serve the parish today.
Photos From the Diocesan Archive: