St. Mary's Mission Church in Fishkill was erected in 1861 at the beginning of the Civil War. On June 29, 1953, a new Parish was established with Monsignor Francis McKeon as its first Pastor. The building of the new school proceeded rapidly. The new School Auditorium was opened for Holy Mass on eve of the Feast of The Assumption of Our Lady, August 14, 1955. In September of that same year the school was opened with the enrollment of 125 pupils and staffed by the Sisters of the Presentation of the Blessed Virgin Mary whose Mother House is Saint Joseph’s in Newburgh. The School has grown continuously since then.