The Sisters of the Precious Blood, founded in Switzerland by Maria Anna Brunner in 1834, began their ministry of prayer and education in Mercer County at Maria Stein, Our Lady of the Rock. Father Francis de Sales Brunner, a Missionary of the Precious Blood, brought the Sisters to America in 1844, and in 1846 established the foundation at Maria Stein, named after a Benedictine Abbey in Switzerland. The convent was the Motherhouse of the Sisters of the Precious Blood until 1923. Relics of the saints were brought to this site from Italy in 1875. The present convent and relic chapel, the National Marian Shrine of the Holy Relics, were built during 1890-1902 and were placed on the National Register of Historic Places in 1976.