Early days St. Mark's was founded in 1865 by Southborough native
Joseph Burnett, a chemist and entrepreneur who amassed a large fortune manufacturing surgical anesthetic, cough syrup, hair tonic, cologne, soda, sausages, bottled milk, and most famously America's first commercially viable
vanilla extract. Burnett was a major civic leader: in addition to establishing St. Mark's, he bankrolled the town's Episcopal church, town hall, library, and its other private school,
Fay School (a junior high). He also helped establish Boston's
Church of the Advent. Along with
St. Paul's School in
Concord, New Hampshire, St. Mark's was one of the first New England schools founded on the
British public school model, as opposed to Revolutionary-era academies like
Andover and
Exeter. The resemblance was intentional, as Burnett had sent his eldest son to
St. Paul's. The Concord school was filled to capacity, and to relieve pressure on its admissions office, its headmaster encouraged Burnett to start a school of his own. New York financier
August Belmont Sr. was an early supporter of the school, and his son
August Belmont Jr. (a St. Mark's alumnus and trustee) eventually donated the school chapel and football field.
Evolution into college-preparatory institution In 1882, William Peck became the headmaster of St. Mark's. He rapidly expanded enrollment and recruited the sons of some of America's richest families. In 1886, the school announced that it had outgrown its facilities and could not accept any more applicants. It moved into a new school building in 1890, which allowed enrollment to increase to 103 students; St. Mark's still uses this building today. The school endured a severe crisis in 1894, when Peck resigned to start
Pomfret School in Connecticut. The staunchly Episcopalian board of trustees clashed with Peck, a layman with (according to Pomfret) "progressive tendencies." Peck took half the faculty and a third of the student body with him. Not coincidentally, Bishop
William Lawrence was president of the board of both St. Mark's and Groton. Lawrence was one of Thayer's early mentors: he influenced him to convert from Presbyterianism to Episcopalianism, and led him to the Episcopalian ministry. A "tireless fundraiser," Lawrence would later lead
Harvard University's first capital campaign in 1904 and raise the money for the
Harvard Business School campus in 1926. Thayer's relationship with Lawrence gave St. Mark's access to the bishop's vast network of donors. Thayer ran the school for the next thirty-six years. He revived and then accelerated St. Mark's institutional trajectory under Peck, building St. Mark's into a distinctly upper-class institution that commanded loyalty "from Boston and the
Knickerbocker families of New York." He continued Peck's project of recruiting the sons of American business titans, adding
William Kissam Vanderbilt and
Joseph Pulitzer to the parent list. A study of the St. Mark's class of 1906 found that 79% of the graduates' fathers were listed in the
Social Register; 59% had attended
Ivy League schools; and 54% worked in finance, law, or other professional services. Thayer also built a strong pipeline to
Harvard College; from 1906 to 1925, an average of fifteen St. Mark's students went on to Harvard every year. (A future headmaster, Edward T. Hall '37, recalled that at the time, colleges "were for the most part willing to accept any boys who could pass the [College] Boards and whose fathers could pay the tuition," so "[s]trong boarding schools[] with capable disciplinarians who knew their subjects ... enjoyed phenomenal success in getting their students into any college they chose.") As the school grew in stature, its enrollment rapidly increased, bouncing back to 131 in 1906 and 191 in 1926. Competition for places was fierce, and Thayer estimated that he received 145 or more applicants for 30–35 openings a year. Edward Hall recalled that "[e]xcept for a handful (it was seven in 1927) of competitive places, priority of application governed likelihood of acceptance. Getting into St. Mark's in the 1920s was a little like getting into the
Somerset Club of Boston: a boy's name was put down within hours or days of his birth if he was to have a chance of acceptance." Parkman reformed the admissions system. He increased the number of students admitted by competitive examination to ten and based the remaining admissions on a mixture of factors, which still included priority of application but also interviews and geographic diversity. However, he was not a natural fundraiser, which was becoming an increasingly important skill for boarding school headmasters, particularly during the worst periods of the
Great Depression, when many St. Mark's families encountered financial difficulties and turned to the school for financial aid. Parkman resigned in 1942 and joined the
U.S. Army Air Corps during
World War II. After the war, he joined the predecessor of the
National Association of Independent Schools; when NAIS was created, he became its first president. William Brewster (h. 1943–48) made the first concerted attempts to change the school's image as an institution of social elites. He increased the number of financial aid students, although he initially did not condition aid awards on academic achievement. He was quickly forced to change course, as college admissions were becoming increasingly competitive, and the 1945–46 school year was the first year that a St. Mark's diploma no longer guaranteed students admission to the college of their choice. In April 1946, the school adopted a policy of awarding financial aid based on scholastic promise, financial need, and geographic distribution. Finding the money to fund a financial aid program was another matter; the school's endowment traditionally lagged its peers', and in 1955 only 11% of the school was on scholarship. In 1956 Brewster's successor William Barber Jr. '28 (h. 1948–68) hired a professional fundraising firm to manage a full-scale fundraising campaign, which more than doubled the size of the school's endowment. St. Mark's began accepting day students in 1944, black students in 1962 (the first black student to matriculate arrived in 1964), and female students in 1977. In the 1960s, the school took its first steps towards coeducation by agreeing to move the all-girls
St. Margaret's School in
Waterbury, Connecticut to Southborough; St. Mark's hoped that St. Margaret's would accommodate female students who wished to attend St. Mark's but could not due to the boys-only policy in force at the time. However, the Connecticut legislature torpedoed the plans. The two schools formally merged five years later. In 2012, the school issued a $25 million bond to renovate its student center and build a new STEM building. In 2021, the school issued a $48 million bond to build a new dormitory housing 150 students, which opened in 2022. St. Mark's was a major filming location for
Alexander Payne's 2023 film
The Holdovers, standing in for the fictional Barton Academy. The production team shot footage in the dining hall, headmaster's office, and basketball court. Although the St. Mark's campus has been modernized since the 1970s (when the movie is set), anachronistic fixtures were temporarily removed to accommodate the production crew. File:Dining hall, St. Mark's School, Southborough, MA - IMG 0665.JPG|Dining Hall (featured in
The Holdovers) File:Performing Arts Center, St. Mark's School, Southborough, MA - IMG 0622.JPG|Performing Arts Center File:St. Mark's School, Southborough, MA - IMG 0646.JPG|Faculty Room (featured in
The Holdovers) == Finances ==