Hillsboro High School is a coed public high school located in Hillsboro, Illinois the county seat of Montgomery County, Illinois, in the United States. HHS is part of the Hillsboro Community Unit School District 3.HistoryIn 1920, it was determined that the existing city high school on Fairground Ave. was no longer acceptable. After reorganizing the school's district, the decision was made to build a new school. The contract for the building designed by architect J. W. Kennedy was awarded on June 22, 1920 at a cost of about $250,000. The construction of the "new" Hillsboro High School was begun in 1920, and the school opened in the fall of 1921.Sitting atop a hill located at 522 East Tremont Street, the north-facing red brick building is surrounded by trees. Through the years, into at least the mid-1960s, the campus was often named as the most beautiful in Illinois.In 1938, the gymnasium, sited to the south of the main building was commissioned with financing for the project coming in part from Works Progress Administration (WPA) fundsThe agriculture building was added in the 1950s to the east of the gym, and the library/cafeteria building opened in 1962 just southeast of the main building.AcademicsIn 2010, Hillsboro High school had an average Act score of 19.6 with a graduation rate of 95.4 percent of their Senior class (which is higher than the state average of 87.8 percent). Since 2010, the school has failed to meet federal education standards set by No Child Left Behind even though in some years the school exceeds some statewide figures. The average class size is 19.6, which is smaller than the Illinois state average of 21.2.