High Quality Content by WIKIPEDIA articles! Harry D. Jacobs High School (commonly referred to as Jacobs or HDJ) is a public high school for students in grades 9 through 12 located in Algonquin, Illinois, a suburb of Chicago, serving students from the west half of the Village of Algonquin and its surrounding areas, including Lake in the Hills, Gilberts, some of Sleepy Hollow, and some of West Dundee, Illinois. The school is located in McHenry County, Illinois but also draws students from Northern Kane County.