Originally built in the mid-nineteenth century as a private school funded by several wealthy Salem and Boston benefactors, John Endecott Memorial gains its namesake from John Endecott the longest-serving governor of the colony of Massachusetts. While the school has a tradition of longevity, what it lacks definitively is a tradition of academic or athletic success. Featuring traditional colonial and New England architecture the school is largely one building with several annexed and added on wings expanded upon throughout the years. With the switch over to a public school, there has been an expansion of interest and enthusiasm in the donor and alumni base and this has seen a large number of renovations and additions to the school. This large amount of investment has seen little payoff and has had unexpected consequences in that a once-thriving Fine Arts department has seen a lot of its own funding diverted for the hope of raising the profile of the STEM fields which still remain struggling. The school's colors are royal blue with gold and white accents. Their mascot is the terriers and they are represented by both the costumed mascot Johnny the Boston and an actual Boston Terrier named Diamond.