Illinois - Area of significance: Exploration/Settlement
| Aplington, Zenas, House |
| Bishop Hill Historic District |
| Black, Margaret, Farmstead |
| Bloomington Central Business District |
| Cairo Historic District |
| Central Geneva Historic District |
| Chicago and Eastern Illinois Railroad Depot |
| Chicago Portage National Historic Site |
| Christenson-Anderson Farm |
| Colby-Petersen Farm |
| Condit, Cortland, House |
| Crego, George M., Farm |
| Durant House |
| Du Sable, Jean Baptiste Point, Homesite |
| Felt, Cyrus, House |
| Flanders House |
| Fort de Chartres |
| Galesburg Historic District |
| Garfield Farm and Tavern |
| Gifford-Davidson House |
| Golconda Historic District |
| Gregg, William L., House |
| Grossdale Station |
| Haight Village Historic District |
| Halderman, Nathaniel, House |
| Hayward-Hill House |
| Henson House |
| Herrick Cobblestone |
| Hodges House |
| Hunt House |
| Iles, Elijah, House |
| Jarrot, Nicholas, Mansion |
| Johnson, Olof, House |
| Lake-Peterson House |
| Macktown Historic District |
| Maeystown Historic District |
| Main Street Historic District |
| Manly-McCann House |
| Martin, Pierre, House |
| McWorter, Free Frank, Grave Site |
| Memorial Washington Reformed Presbyterian Church |
| Menard, Pierre, House |
| Michigan-Wacker Historic District |
| Millburn Historic District |
| Morris Wide Water Canal Boat Site |
| Muller House |
| Naperville Historic District |
| Naples Archeological District |
| Nauvoo Historic District |
| New Philadelphia Town Site |
| Nisbet Homestead Farm |
| Noble-Seymour-Crippen House |
| North Geneva Historic District |
| Patton, John, Log Cabin |
| Paxton First Schoolhouse |
| Petersburg Historic District |
| Peterstown House |
| Phelps, Alexis, House |
| Plainfield Halfway House |
| Power Farmstead |
| Rehnstrom, August and Margaretha, House |
| Rock Island Arsenal |
| Rockton Historic District |
| Rogers, Orson, House |
| Rutherford, Dr. Hiram, House and Office |
| Scott, Lyman, House |
| South Side German Historic District |
| Starved Rock |
| Stearns-Wadsworth House |
| Stephenson, Benjamin, House |
| Steward, Lewis, House |
| Stickney, George, House |
| St. James Catholic Church and Cemetery |
| Stolp Island Historic District |
| Stolp Woolen Mill Store |
| Terwilliger House |
| Trobaugh-Good House |
| Ulery, Eli, House |
| Union House |
| Vial, Robert, House |
| Warner, Seth, House |
| Wenner, Charles, House |
| Wilson, Judge Isaac, House |
Data from United States Park Service and Wikidata
