Built in 1882 near the present site of Central Elementary School at 9th Street and E Avenue, National School was the South Bay's first high school. National's successor, National City High School, was built in 1908 around that same location, where Central Elementary School now stands. To accommodate the growing population of high school students, Sweetwater Union High School was built in 1921 at 2900 Highland Avenue. The present day administration building was originally two-stories with the library upstairs.
