Question: Which two prep schools are located in the birthplace of the one known for the order given to soldiers to conserve their limited stocks of ammunition?

Context articles: Manter Hall School
William Prescott
St. John's School (Texas)
Independent school (United Kingdom)
Handcross Park School
Groton, Massachusetts
University Prep Schools
Mid-Atlantic Prep League
Boarding school
Hukamnama

Manter Hall School was a private prep school located in Cambridge, Massachusetts that existed between 1884 and 1996.
 Founded in 1884 by William W. Nolen (Harvard, Class of 1884) as Nolen's Tutoring School, the original mission of the school was to tutor Harvard undergraduates to prepare them for mid-term and final examinations.
 The curriculum expanded in the 1930s to include preparing students for Harvard's entrance exam.
 Manter Hall eventually evolved into an unorthodox prep school that prepared students who were unable to fit into traditional high schools and prep schools.
William Prescott (February 20, 1726 – October 13, 1795) was an American colonel in the Revolutionary War who commanded the patriot forces in the Battle of Bunker Hill.
 Prescott is known for his order to his soldiers, "Do not fire until you see the whites of their eyes", such that the rebel troops may shoot at the enemy at shorter ranges, and therefore more accurately and lethally, and so conserve their limited stocks of ammunition.
 It is debated whether Prescott or someone earlier coined this memorable saying.
St. John's School (also known as St. John's or SJS) is a coeducational independent school in Houston, Texas, United States, presenting a 13-year sequence of university preparatory training.
 The School was founded in 1946 and is a member of the Houston Area Independent Schools, the Independent Schools Association of the Southwest (ISAS), and the Southwest Preparatory Conference (SPC).
 Though situated adjacent to St. John the Divine church, St. John's claims no religious affiliation.
 It has been coeducational since its founding and has produced many notable alumni.
 Noted for its selectivity and academic rigor, St. John's has been described by Forbes.com as one of "America's Elite Prep Schools" and listed by the "Wall Street Journal" as among schools in the United States with the largest percentages of graduates attending a handful of highly selective universities.
In the United Kingdom, independent schools (also private schools) are fee-paying private schools, governed by an elected board of governors and independent of many of the regulations and conditions that apply to state-funded schools.
 For example, pupils do not have to follow the National Curriculum.
 Many of the older, expensive and more exclusive schools catering for the 13–18 age-range in England and Wales are known as public schools as defined by the Public Schools Act 1868.
 The term "public" being derived from the fact that they were open to pupils regardless of where they lived or their religion (while in many other countries a public school is run by the state or municipality.)
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 Prep schools, (or preparatory school) educate younger children up to the age of 13 to "prepare" them for entry to the public schools and other independent schools.
 Some former grammar schools converted to an independent fee paying model following the 1965 Circular 10/65 which marked the end of their state funding, others converted into comprehensive schools.
Handcross Park School is an independent co-educational preparatory school in Handcross, between Crawley, Horsham and Haywards Heath in West Sussex, England.
 The school provides private co-education from the Nursery aged 2, through Pre-Prep and into Prep until aged 13, with a mix of day pupils and weekly and full boarders.
 The school traces its origins back to 1887, and moved to its current site in 1968.
 The School was formed as a result of the merger of two prep schools , Newells and Desmoor.
 Newells had to move to this site following a fire in which one pupil died.
 The staff and pupils of Desmoor then moved from Ewhurst in Surrey.
 Originally there were two headmasters, Captain Peter Hope-Lang and Mr McNeil, until Hope-Lang's death in 1970.
 For a time the school was also known as Newells and Desmoor School.
Groton is a town in northwestern Middlesex County, Massachusetts, United States.
 The population was 10,873 at the 2012 town census.
 It is home to two prep schools: Groton School, founded in 1884, and Lawrence Academy at Groton, founded in 1792.
 The historic town was a battlefield in King Philip's War and Queen Anne's War, experienced incidents of insurrection during Shays's Rebellion, and was the birthplace of William Prescott, who commanded the colonial forces at the Battle of Bunker Hill.
University Prep Schools (U Prep Schools) is a K-12 charter school system headquartered in the New Center area of Detroit.
 It has two districts within its system: University Preparatory Academy (UPA) and University Prep Science & Math (UPSM).
The Mid-Atlantic Prep League, also known as the MAPL, is a sports league with participating institutions from prep schools in New Jersey and Pennsylvania in the United States.
 The league comprises schools known for their academic rigor, but the quality of play in all sports is fairly high.
 MAPL schools are allowed to have a limited number of post-graduates (student-athletes who have already graduated from high school and are taking an intermediate step between high school and college) on their rosters.
A boarding school is a pre-university level school where most or all of the students take up residence when school is in session.
 The word ”boarding” is used in the sense of "room and board," i.e., lodging and meals.
 Boarding schools are also known as University or College Preparatory Schools, aka “Prep Schools.”
 Some boarding schools also have day students who attend the institution by day and return to their families in the evenings.
A Hukamnama refers to a hymn from the Guru Granth Sahib which is given as an order to Sikhs or a historical order given by one of the Gurus of Sikhism.