St. Mark’s School is a coeducational, Episcopal, preparatory school, situated on 250 acres (1.0 km²) in Southborough, Massachusetts, 25 miles (40 km) from Boston. It was founded in 1865 as an all-boys school by Joseph Burnett, a wealthy native of Southborough who developed and marketed the world-famous Burnett Vanilla Extract. Girls have attended since the 1970s. St. Mark's is a member of the Independent School League, and the second-oldest of the five elite prep schools collectively termed St.