Question: South Berwick is home to a college preparatory school founded in which year ?

Context paragraphs:
Brebeuf Jesuit Preparatory School: Brebeuf Jesuit Preparatory School (BJPS) is a private college preparatory school founded by the Jesuits and located on the northwest side of Indianapolis.  It is a part of the Midwest Province of the Society of Jesus and geographically located within the Roman Catholic Archdiocese of Indianapolis.

TMI — The Episcopal School of Texas: TMI — The Episcopal School of Texas (in full Texas Military Institute) is a selective coeducational Episcopal college preparatory school with a military tradition in San Antonio, Texas for boarding and day students.  It is the flagship school, and sole secondary school, of the Episcopal Diocese of West Texas.  TMI is the oldest Episcopal college preparatory school in the American Southwest.  Founded as West Texas School for Boys, the school was later known as West Texas Military Academy, and popularly nicknamed 'West Point on the Rio Grande', though it is several hours from the Rio Grande itself.

Northwestern Preparatory School: Northwestern Preparatory School was a four-year Lutheran high school founded in 1865 and located in Watertown, Wisconsin.  The school merged with Martin Luther Preparatory School in 1995 to become Luther Preparatory School.  It was affiliated with Northwestern College of Watertown, which merged with Dr. Martin Luther College of New Ulm, Minnesota in 1995 to become Martin Luther College.

St. John Vianney High School (Kirkwood, Missouri): St. John Vianney High School (a.k.a. Vianney High School, or simply Vianney) is a private, all male, Catholic college preparatory school located in Kirkwood, Missouri.  It is located in the Roman Catholic Archdiocese of Saint Louis.  The school was founded by the Society of Mary (Marianists), a religious order of priests and brothers who continue to run the school.  The Marianists also run a number of other St. Louis area high schools including Chaminade College Preparatory School and St. Mary's High School.

South Berwick, Maine: South Berwick is a town in York County, Maine, United States.  The population was 7,220 at the 2010 census.  South Berwick is home to Berwick Academy, a private, co-educational university-preparatory day school founded in 1791.

Saint Joseph's Preparatory School: St. Joseph's Preparatory School, often known as "the Prep", is an urban, private, Catholic, college preparatory school founded in 1851 in Philadelphia, Pennsylvania, within the Archdiocese of Philadelphia.  It is run by the Jesuits. Philadelphia mayors Michael Nutter, William Green III, Jim Kenney and many other members of the city government matriculated from the Prep, which remains near the heart of Philadelphia.

Worksop College Preparatory School: Worksop College Preparatory School, Ranby House is a co-educational independent preparatory, day and boarding, school for boys and girls aged 3 to 13.  It was founded by Nathaniel Woodard and is a member of the Woodard Schools.  The school is the feeder to Worksop College which is located some 5 miles away.  The school currently has around 260 pupils and the Head Master is Christian Pritchard.  The school has two main parts, the 'Pre-Prep' (3–7 years of age) and the 'Preparatory School'.  This 'Preparatory School' is then divided further into the four groups or houses: St Alban; St Benedict; St Columba; and St Dunstan.

St. Stephen's &amp; St. Agnes School: St. Stephen's & St. Agnes School (SSSAS) is an independent Episcopal coed private college preparatory school in Alexandria, Virginia.  The school was created from the 1991 merger of St. Agnes School (a girls school founded in 1924) with St. Stephen's School (a boys school founded in 1944).  The school consists of three campuses within a 1.5-mile radius.  The Lower School, grades JK-5, is located on Fontaine Street; the Middle School, grades 6-8, is located on Braddock Road; and the Upper School, grades 9-12, is located on St. Stephen's Road.

Tennessee Christian Preparatory School: Tennessee Christian Preparatory School (TCPS) is a private Christian college preparatory school located in Cleveland, Tennessee.  In addition to being the only state-accredited private college preparatory school in the immediate area.

Berwick Academy (Maine): Berwick Academy is a college preparatory school located in South Berwick, Maine.  Founded in 1791, it is the oldest educational institution in Maine and one of the oldest private schools in North America.  The school sits on a 72-acre, 11-building campus on a hill overlooking the Salmon Falls River, near the border between Maine and New Hampshire.  Approximately 565 students in grades Pre-K through 12 (and Post-Grad) attend this coeducational day school, from approximately 60 communities in the surrounding regions of southern Maine, southeastern New Hampshire and northeastern Massachusetts.

Supporting paragraphs: South Berwick, Maine Berwick Academy (Maine)
Answer: 1791