Union Elementary School was originally Union Community School. It began with a wooden school house with its first Grade I class in 1916.A year passed enrolment increased and combination classes were created wherein Grade 1&2 had their classes in the morning while Grade 3 & 4 in the afternoon because they were using only one classroom and only one teacher was in charge. Some years later more children were enrolled and the school catered school children from Grades I to VI. The community then built wooden classrooms needing more space. It was then that the owners of the farmland where the school is now occupying voluntarily donated part of their farmlands for the construction of school buildings. The donors were Mr. Isabelo Riego, Mrs. Elija Sensano Burigsay, Sanjera San Nicolas, Mr. Gregorio Riego, Mr. Eulogio Agnir, Mrs. Maria Villaflor, Mr. Vicente Iduria, Miss Lucia Agmata, Mr. Ramon Sagucio and Mr Jose Nagtalon. Others donated a part of their farms in later years when the school created high school. There were many enrollees because of the children coming from the nearby barangays of Lablabig, Mabnang, Kilkiling San Vicente, Bacsay Cataraoan and Barangay Cadcadir. The name Union Community School was used until an order came from the Department of Education that the school be called Union Elementary School.