Stephen Decatur High School was a public high school in Decatur, Illinois, United States, which existed from 1862 to 2000. Stephen Decatur High School was simply known as Decatur High School until 1957, when the city's only high school was joined by Lakeview High School, and MacArthur and Eisenhower High Schools, which were newly constructed to accommodate the student population that was exploding as a result of the post-World War 2 "baby boom".