Complex sentence: It was the largest and most modern school in the county upon completion, the first new public high school opened since the completion of West Williamson High in 1956 (later renamed Fairview High School).
Split into simpler sentences: It was the largest and most modern school in the county upon completion. Page was also the first new public high school opened in nearly 20 years since the completion of West Williamson High in 1956 (now known as Fairview High School).