Illinois - Area of significance: Commerce
| Homestead, The |
| Hossack, John, House |
| Hotel Arthur |
| Hotel Aurora |
| Hotel Belleville |
| Hotel Kaskaskia |
| Hotel Roodhouse |
| Hotel Stratford |
| Hotel Waukegan |
| Hotel Windermere East |
| Hunt House |
| Hyde Park-Kenwood Historic District |
| Iles, Elijah, House |
| Illinois Iron Furnace |
| Illinois State Bank Building |
| Illinois Traction Building |
| Inman Hotel |
| International Harvester Building |
| International Harvester Showroom and Warehouse |
| Jacksonville Downtown Historic District |
| Jennings Ford Automobile Dealership |
| Jerseyville Downtown Historic District |
| Johnson, Olof, House |
| Joliet, Louis, Hotel |
| Jones House |
| Kamp Store |
| Karcher Hotel |
| Keithsburg Historic District |
| Kewanee Hotel |
| LaHarpe Historic District |
| Lake Bluff Uptown Commercial Historic District |
| Lamoine Hotel |
| LaSalle Downtown Commercial District |
| LaSalle Street Auto Row Historic District |
| LeClaire Hotel |
| Lemont Downtown Historic District |
| LeRoy Commercial Historic District |
| Libertyville Downtown Historic District |
| Lincoln Courthouse Square Historic District |
| Lock and Dam No. 13 Historic District |
| Lock and Dam No. 15 Historic District |
| Lock and Dam No. 17 Historic District |
| Lock and Dam No. 18 Historic District |
| Lock and Dam No. 21 Historic District |
| Lockport Historic District |
| Loop Retail Historic District |
| Louisville and Nashville Depot |
| Macktown Historic District |
| Macomb Courthouse Square historic District |
| Magill House |
| Maid-Rite Sandwich Shop |
| Main Street Historic District |
| Malvern Roller Mill |
| Marshall Field and Company Store |
| Marshall Field Company Store |
| Mary's River Covered Bridge |
| Massie Variety Store |
| Maxwell-Briscoe Automobile Company Showroom |
| McWorter, Free Frank, Grave Site |
| Mershon, Joab, House |
| Mid-City Trust and Savings Bank |
| Milk, Lemuel, Carriage House |
| Miller-Davis Law Buildings |
| Millikin, James, House |
| Mineola Hotel |
| Moline Downtown Commercial Historic District |
| Monmouth Courthouse Commercial Historic District |
| Montgomery Ward Company Complex |
| Monticello Courthouse Square Historic District |
| Morris Downtown Commercial Historic District |
| Morrison Main Street Historic District |
| Morris Wide Water Canal Boat Site |
| Motor Row Historic District |
| Mount Lookout |
| Mount Morris Downtown Historic District |
| Mount Sterling Commercial Historic District |
| Muller House |
| Murphysboro Downtown Historic District |
| Newcomb, Richard F., House |
| North Eighth Street Plaza |
| North Geneva Historic District |
| North Side Historic District |
| North Wells Street Historic District |
| Old Stone Gate of Chicago Union Stockyards |
| Oliver Building |
| Oregon Commercial Historic District |
| Ottawa Commercial Historic District |
| Overton Hygienic Building |
| Palestine Commercial Historic District |
| Peabody, Francis Stuyvesant, House |
| Peck and Hills Furniture Company Warehouse |
| Peoples Gas Building |
| Peoples National Bank Building-Fries Building |
| Peoria Mineral Springs |
| Peotone Mill |
| Pine Craig |
| Pioneer Trust and Savings Bank |
| Plainfield Halfway House |
| Plano Hotel |
| Post House |
Data from United States Park Service and Wikidata
