Complex sentence: In 1988, the school constructed the Sims building to house their Early Learning program (traditionally elementary school), and in 1996 it built the Arnold building for its Middle Learning program (traditionally middle school) as well as a gymnasium.
Split into simpler sentences: In 1988, the school constructed the Sims building to house the Early Learning program (traditionally elementary school). In 1996 it built the Arnold building for its Middle Learning program (traditionally middle school) as well as a gymnasium.