| The school went ahead. The house along Arrow Street, built for William Winthrop in 1811, was immediately converted to a convent for the Sisters of St. Joseph and temporary classrooms for young children while a proper school was erected on the site. The new construction was built by the firms of Driscoll and O'Brien from the plans of Patrick W. Ford, an Irish architect who came to the United States just after the Civil War. He is credited with a large number of Catholic churches, schools, and convents including Sacred Heart in East Cambridge and the old St. John's church and school in North Cambridge (originally built for St. Peter's in 1891). Three sisters began instruction in the first year of the new school with an enrollment of 198. Fr. Orr set a high standard of education at St. Paul's School. The class of 1895, the first class to graduate from a full tenure at St. Paul's, fulfilled this expectation in a very decisive manner, when it reported for the entrance examination to the public high school. Of the twenty-three students who took the examination, twenty passed unconditionally. After five years of similar performance by St. Paul's graduates, the School Board at the recommendation of the Superintendent of Schools, voted to accept St. Paul students on the sole basis of their diplomas.
The school stood for a century, but its twelve classrooms, two large meeting-rooms, and first floor hall for 800 were soon insufficient and had to be augmented by an adjacent brick building, known most recently as the Catholic Student Center. On the McKay estate, Fr. Orr apparently still intended to build a new church, and for that reason the school building had been set back in the block leaving open the site where in fact the current church stands.
School enrollment reached its peak in 1914, when the parish celebrated the twenty-fifth anniversary of the school and the new church was being planned. In that year, 990 pupils were registered for the parish school and 412 came for Sunday classes. However, the population of the neighborhood began to decline as residents moved to the suburbs and Harvard purchased land along the Charles River, so that in each subsequent decade the school lost about 150 students. By the 1960's, the school faced not only declining attendance but also a shortage of nuns and was relying increasingly on lay teachers. On June 28, 1968, the remaining few Sisters of Saint Joseph vacated their convent. In 1974 the last class of the St. Paul's parish school graduated, but in a reduced form the enthusiasm and standards of excellence of the Sisters of Saint Joseph continues today in their association with the Boston Archdiocesan Choir School.
| | 
At the time it was built in 1889, the sixteen-room parish school was not large enough to accommodate all the classes. |
|