The district was officially established November 1, 1934, by the States Commissioner of Education. Bellmore-Merrick Central High School District was known as C.H.S.D. 3 until May 1973, when it officially adopted the name reflecting its geographic location. This change was required of all districts by the State Education Department.
One hundred fifty freshman students entering high school in September 1935, studied with five faculty members in a renovated six-room school house on Bedford Avenue. Mr. Sanford H. Calhoun served as principal. Wellington C. Mepham High School opened in 1937 with an enrollment of 741 students.
Jerusalem Avenue Junior High School and Merrick Avenue Junior High School were opened in 1954. In 1958, the Sanford H. Calhoun High School and the Grand Avenue Junior High School were opened. In 1963, an addition was placed on the Mepham High School. Brookside Junior High School opened in September 1964, and John F. Kennedy High School opened in September 1966. There were then over 10,000 students in the district. There are now approximately 6,100 students in the district. Brookside and Jerusalem Avenue have been closed due to declining enrollment. Today, Jerusalem Avenue is rented to Nassau BOCES and the district’s central office is at Brookside, along with several tenants. The rental space generates additional income for the district. The Meadowbrook Alternative Program (MAP) also resides at Brookside.