Illinois - Area of significance: Politics/Government
| Libertyville Town Hall |
| Lincoln Courthouse Square Historic District |
| Lincoln Home National Historic Site |
| Lincoln's New Salem Village |
| Lincoln Tomb |
| Livingston County Courthouse |
| Lloyd, Henry Demarest, House |
| 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 |
| Lovejoy, Owen, Homestead |
| Macomb Courthouse Square historic District |
| Main Street Historic District |
| Manly-McCann House |
| Marine Chapter House |
| Marion Veterans Administration Hospital Historic District |
| Memorial Hall |
| Mercer County Courthouse |
| Metamora Courthouse |
| Miller-Davis Law Buildings |
| Monmouth Courthouse Commercial Historic District |
| Montgomery County Courthouse |
| Monticello Courthouse Square Historic District |
| Morgan County Courthouse |
| Morgan-Wells House |
| Moultrie County Courthouse |
| Mount Lookout |
| Mount Pulaski Courthouse |
| Municipal Courts Building |
| Murphysboro Downtown Historic District |
| Oak Park Village Hall |
| Old Cahokia Courthouse |
| Old Fire Station |
| Old Iroquois County Courthouse |
| Old Main, Knox College |
| Old Market House |
| Old State Capitol |
| Oregon Commercial Historic District |
| Patton, John, Log Cabin |
| Pennsylvania Avenue Historic District |
| Pontiac City Hall and Fire Station |
| Post House |
| Power Farmstead |
| Princeton Chapter House |
| Princeton South Main Street-Courthouse Square Historic District |
| Putnam County Courthouse |
| Rainey, Henry T., Farm |
| Ratcliff Inn |
| Raymond M. Hilliard Center Historic District |
| Reagan's, Ronald, Boyhood Home |
| Reorganized Church of Jesus Christ of Latter Day Saints |
| Robinson-Stewart House |
| Rochelle Downtown Historic District |
| Rohrbough, Calendar, House |
| Sandwich City Hall |
| Scott-Vrooman House |
| Soldiers and Sailors Memorial Hall |
| South Side Community Art Center |
| Stephenson, Benjamin, House |
| Stevenson, Adlai E., I, House |
| Stevenson, Adlai E., II, Farm |
| Stevenson House |
| St. Nicholas Hotel |
| Table Grove Community Church |
| Taylorville Courthouse Square Historic District |
| Thebes Courthouse |
| Trumbull, Lyman, House |
| Turner Town Hall |
| United States Housing Corporation (U.S.H.C.) Historic District |
| United States Post Office-Chicago |
| Unity Hall |
| University Apartments |
| Ursa Town Hall |
| Vandalia Statehouse |
| Vermont Historic District |
| Village of Davis Junction Town Hall |
| Washburne, Elihu Benjamin, House |
| Washington Park Historic District |
| Wells-Barnett, Ida B., House |
| West Frankfort City Hall |
| West Loop-LaSalle Street Historic District |
| Whitney, William, House |
| Williams, James Robert, House |
| Wilmette Village Center Historic District |
| Woman's Christian Temperance Union Administration Building |
| Wood, John, Mansion |
| Zion Chapter House |
Data from United States Park Service and Wikidata
