Year Opened: 1818

St. Louis University High School just happens to be America's oldest secondary educational institution west of the Mississippi River.

Founded by Bishop Dubourg, the bishop of St. Louis in the early 1800s, the private Jesuit Catholic high school was originally known as St. Louis Academy. But the boys-only school has come a long way from the original one-story house it was held in, with about 980 students now in attendance as well as a college division.

Oldest High School in Every State | FamilyMinded