St. Anthony was established in 1904 as an Italian parish. The origin of the parish can be traced to the arrival of Italian immigrants to the area beginning in 1890. Starting in 1895, the pastor of the territorial parish of Transfiguration accommodated the local Italian community by inviting Italian speaking priests to their parish to celebrate Mass and hear confessions in Italian. However, the Italians wanted their own parish and petitioned the bishop for one. In May of 1904 the bishop assigned the responsibility of forming a mission in Monongahela to the pastor of Mother of Sorrows parish, Charleroi.
The first Mass of the new mission was celebrated in the Anton Building in May of 1904. Soon afterwards, work began on a church, which was dedicated on December 17, 1905. In January of 1908, the parish became independent with the appointment of a resident pastor.
The parish suffered two blows in 1913. On February 2, 1913, the church was destroyed in a fire. Two months later, the pastor returned to Italy and the parish reverted to a mission of Mother of Sorrows again.
While the church was being rebuilt, Mass was celebrated in a rented storeroom. On December 10, 1915, a new resident pastor was assigned to the parish. The first task of the new pastor was the rebuilding the church. In April of 1917, the new church was dedicated.
This church served the congregation for three decades. Eventually, the parish outgrew its facilities. On May 2, 1949, ground was broken for a new church. On November 13, 1949, the cornerstone was laid and on May 14, 1950 the church was dedicated. The old church was renovated into a parish hall and used as such until 1957 when it was converted to a convent.
Unfortunately, the late 20th century saw a decline in heavy industry in the area and a subsequent loss of population. By the early 21st century, it became obvious that the area could no longer support the number of parishes then in existence. In October of 2007, the parishes in Monongahela, Charleroi and Donora took part in a two year study to look at the future of the Church in the region. The study considered the demographics, spiritual needs, financial stability and an assessment of the parish buildings in the three communities. The study developed several recommendations, including the recommendation to merge the two parishes in Monongahela. The bishop accepted this recommendation and on August 15, 2011 St. Anthony Parish and Transfiguration Parish in Monongahela merged to form the new St. Damien of Molokai Parish. The new parish kept both churches open pending a two year study to determine if the parish needed to maintain both churches.
The study determined that it was not feasible for the parish to maintain two church buildings. However, the parish was unable to come to a consensus as to which of the two churches should remain open.The parish then asked the bishop to make the final decision and, after inviting feedback from the individual parishioners, he decided to keep Transfiguration Church open and to close St. Anthony Church. The final Mass of the church was celebrated on April 27, 2014 and the building was formally closed the next day.
