In 1912, a three room building was constructed at the rear of the church. When the school opened in September, there were 104 students in grades one through three registered for school. Initially, there were two teachers that taught the student body for two years until the arrival of the Precious Blood Sisters in 1914, at the request of the pastor, Father Ermenegildo Senese. At this time, an addition was added to the school. In 1915, a second story to the school was constructed. Students helped select the school mascot, the Crusaders, and the school colors of blue and red. St. Mary's Church officially was named Our Lady of Mount Carmel in 1925, after a larger church was built.
The new school grew rapidly in enrollment during the early years. In 1920, the enrollment reached 365 students. The largest graduating class in the school's history was during 1930 with a total of 54 students. By 1940, a brand new fire-proof school was erected. It took seven more years before the large gymnasium was completed. Then in 1947, the school was expanded to add a library, cafeteria, and an extra classroom. Around this time, The School Sisters of Notre Dame took over the teaching responsibilities.
The Catholic High School opened in 1947, but was forced to close its doors three years later due to low enrollment. That same year, The School Committee was formed to help raise funds for the school, as it still does today. In 1960, the school yard was blacktopped, and curriculum was expanded to include Spanish and music. The following year ushered in school uniforms for all female students.