Oak Grove was one of five one room schools in Upper Oxford Township. A student, PFC. Jesse L. Thomas, a WWII Marine, planted the U.S. flag on Okinawa in 1945. Since 1893, Oak Grove educated three generations of the Bertha Cochran Gray family. Ethel Hilton Gray, a student from 1917 to 1925, returned as teacher from 1948 to 1954.