St. Patrick's offered classes from the 3rd to 8th grade. Since 1937, most of the students were boys and boarders but there were a few girls and boys day students, from local towns and municipalities.

The school was closed in June 1988 after it was determined that it was a sound course of action. The decline in the interest of boarding military academies and the high cost of monthly tuition was the principal cause of the school's demise.

The school was established in 1937 and located at St. Theresa’s Hall, next to the Main Chapel Building and was originally named St. Patrick's Academy.  In 1950, the name was changed to St. Patrick’s Semi-Military Academy, after the school established a relationship with the United States Military Academy at West Point. 

In 1951, the Classroom Building was built and converted from an existing large barn.

In 1959, the Sisters purchased additional acreage across the road to build the Academy Residential Building in 1960.  

The Alumni of St. Patrick's just recently found out that the school was never located in Harriman, New York, but in Monroe, New York. The address of the school was covered by the Harriman Post Office only.

The entire St. Patrick's campus was originally built in 1922, when the Pallottine Sisters opened the Mother House in the United States and made Harriman, New York, their home.

Following the school's closure in June 1988, the crosses on top of both buildings were removed. The facilities were later rented to the Monroe-Woodbury Central School District and much later other schools and organizations.

In 2013, in anticipation of selling the property, the entire St. Patrick Military Academy Campus, including the Sister's Residences and Old Chapel were demolished. The sisters moved to new quarters within the property. The property has not been sold, as of June, 2015. The Cornerstone of the Dormitory Building (1960) survived and it is being stored for history.

The Educational Curriculum of the school included 3rd Grade to 8th Grades Grammar School. This included Mathematics, History, English, Geography and Civics. Monsignor Sullivan and the sisters taught religion and the Catechism.

The Bishop came to the school each Easter for Confirmation and Monsignor Sullivan took care of First Holy Communion.

Catholic Mass was said each day, at the school for the sisters and the students could attend, if requested. Mass was said for the Regiment on Sunday, if it was a closed weekend, with no free time at home.

The school had a Basketball Team for a while that entered into competition with other local schools and other Pallottine Academies. The school had company level baseball teams, but nothing of a serious nature. It was basically considered "Play Time". The school took the children to the then Ford Motor Plant in Mahwah, New York. The school took the children to go bowling in Monroe, New York. However, the school concentrated its activities surrounding the Glee Club and its Marching Band.

The Glee Club was the best of its class. They performed each year at the Center Concourse of the Port Authority of New York and New Jersey Bus Terminal, in front of the Golden Statue of the Skating Rink at Rockefeller Center and in 1964 at the New York Pavilion of the World's Fair in Flushing, Queens, New York.

The entire Regiment of Cadets marched each year in the New York City St. Patrick's Day parade and Columbus Day parade. The school also sent partial units to include the color guard and the marching band to local Memorial Day events in Monroe, New York.

In 2007, an idea to create the St. Patrick’s Military Academy Alumni Association was born.  It is going to be a way to treasure the history of the school and good memories of the past, to include photographs and documents.  The intention is to have a reunion, as soon as possible. 

This idea was presented to the Sisters and they were delighted.

On December 7, 2017 the Association was incorporated under the laws of the State of New York. 

We call on all Graduates of the Academy, to Contact Us and register yourselves as Alumni’s.  Please check and search your old boxes for your school photos and documents and memorabilia from years past.