Illinois - Role: Building
| Hotel Kaskaskia |
| Hotel Roodhouse |
| Hotel St. Benedict Flats |
| Hotel Stratford |
| Hotel Waukegan |
| Hotel Windermere East |
| House at 380 Chiltern Drive-Deerpath Hill Estates |
| House at 965 Castlegate Court-Deerpath Hill Estates |
| Hubbard House |
| Hulburd, Joel H., House |
| Hull House |
| Hull, William H., House |
| Humer Building |
| Humphrey, John, House |
| Hunter-Hattenburg House |
| Hunter, Lucinda, House |
| Hunt House |
| IBM Building |
| Iles, Elijah, House |
| Illinois Central Railroad and Toledo, Peoria, and Western Railroad Freight House |
| Illinois Central Railroad Depot |
| Illinois Central Railroad Depot |
| Illinois Central Railroad Depot |
| Illinois Central Railroad Passenger Depot |
| Illinois Department of Mines and Minerals-Springfield Mine Rescue Station |
| Illinois National Guard Armory |
| Illinois State Bank Building |
| Illinois State Capitol |
| Illinois State Police Office, Pontiac |
| Illinois Traction Building |
| Illinois Traction System Mackinaw Depot |
| Immaculata High School |
| Immanuel Evangelical Church |
| Immanuel Lutheran Church and Parsonage |
| Inland Steel Building |
| Inman Hotel |
| International Corset Company Building |
| International Harvester Building |
| International Harvester Showroom and Warehouse |
| International Tailoring Company Building |
| Irving, James B., House |
| Ives, Gideon, House |
| Jackson County Courthouse |
| Jackson Shore Apartments |
| Jacksonville Labor Temple |
| Jacksonville Public Library |
| Jacoby, Lysander, House |
| James C. Curtis & Co. Building |
| James E. Plew Building |
| James, Jean Butz, Museum of the Highland Park Historical Society |
| Jameson, H.D., House |
| Jarrot, Nicholas, Mansion |
| Jarvis, William W., House |
| Jehle, Louis, House |
| Jennings Ford Automobile Dealership |
| Jensen, Chris, Round Barn |
| Jersey County Courthouse |
| Jerseyville First Presbyterian Church |
| Jewelers' Building |
| Jewish People's Institute |
| Johnson County Courthouse |
| Johnson, Olof, House |
| Joilet YMCA |
| Joliet, Louis, Hotel |
| Joliet Municipal Airport |
| Joliet Township High School |
| Jones House |
| Jubilee College |
| Judd, C. H., House |
| Judson, The |
| Kamp Store |
| Kankakee County Courthouse |
| Kappa Delta Rho Fraternity House |
| Kappa Kappa Gamma Sorority House |
| Kappa Sigma Fraternity House |
| Karcher Hotel |
| Kehilath Anshe Ma'ariv Synagogue |
| Kendall County Courthouse |
| Kenilworth Club |
| Kennicott's Grove |
| Kent, Sydney, House |
| Kenwood Evangelical Church |
| Kewanee Hotel |
| Kewanee Public Library |
| Keys, Alvin S., House |
| Keystone Building |
| Kickapoo Building |
| Kimball, William W., House |
| King, Patrick J., House |
| Kirk, Col. Edward N., House |
| Kleinkopf, Clarence, Round Barn |
| Klunk, Michael, Farmstead |
| Knobeloch-Seibert Farm |
| Knox County Courthouse and Hall of Records |
| Knox County Jail |
| Knuessl Building |
| Koerner, Gustave, House |
| Kosciuszko Park Field House |
| Krause Music Store |
| Kuppenheimer, Louis B., Jr., House |
Data from United States Park Service and Wikidata
