Cedar Grove School is a surviving one room schoolhouse built on the original one thousand acre property of Thomas Warne, one of the 24 proprietors of East Jersey. Several generations of the Warne family taught at the school, and this location has been a school site since 1851. Two other school buildings stood here at different times before being moved elsewhere. The present wooden building was erected in 1885. It was originally clapboard, and the wooden shingles on the building today were added in the early 1800s. The building originally had three windows on the east side and three on the west side, along with a small porch, and early in the 20th century a roof was added over the interior. It retains its original wainscoting, slate blackboards, heating stove, and a platform for the teacher’s desk. Electricity was installed in the late 1920s. The school closed in 1948, and over the years its enrollment ranged between 20 and 30 pupils. In 1897, through the efforts of the Middlesex County Superintendent of Schools, teachers, and students, a USA flag was furnished for all schools.