Plymouth Elementary School opened its doors to students in the middle of the school year in 1952. It was built because the closest elementary school, Santa Fe, was overcrowded. When Plymouth first started there were nine teachers, nine regular classes, and a class for handicapped children.
Plymouth School was built in lower Monrovia in an area called Mayflower Village. Mayflower Village used to be called "Cow Town" because two large dairies, Mountain View and Alta Dena Dairy, were close neighbors. On rainy days the smell on the playground could be overwhelming. Plymouth was probably named after Plymouth Rock where the Pilgrims who sailed on the Mayflower landed in 1620.