John M. Sweeney built the first Church of the Sacred Hearts of Jesus and Mary in 1866 for a sum of $2,500. It was located on the eastern slope of Catholic Hill, and was a frame building 22 x 66 feet. On October 10, 1866 as the church was nearing completion, Father Francis X. Kuppens was assigned to Helena as pastor and Father Jerome D'Aste was assigned as his assistant. The church was completed and formally dedicated to the Sacred Hearts of Jesus and Mary. On November 4, 1866, three days after the first Mass was said in the new church, a meeting was held. At that meeting they drew up and passed a resolution giving all right and title of the church buildings and lands then in their possession to the Society of Jesus (the Jesuits). In 1874, this little frame church was moved back away from its original site while a new church was constructed. In time it was converted into a parochial school and meeting hall.

On August 16, 1874, a building committee was appointed for the construction of a brick structure with cut granite facings, upon a stone foundation, 43 x 95 feet, with an 18 x 22-foot sacristy. The cornerstone of the new church was blessed on September 20, 1874. The church was completed on April 9, 1876, and dedicated to the Sacred Hearts of Jesus and Mary; the cost was $28,413.22. This church became Montana's first Cathedral in 1884. On November 1, 1914, Bishop Carroll preached the farewell sermon to the last Sunday congregation at the Old Cathedral of the Sacred Hearts. This first Cathedral has since been torn down.

On Christmas day 1914, the new Cathedral of St. Helena was dedicated but it was not complete until May 1924 when the last of the clear windows was replaced with the stained glass. Finally on June 3, 1924, the building was consecrated.



All burials in the vault were moved to other locations.