Illinois - Role: Building
| Chana School |
| Chapin and Gore Building |
| Charles Warrington Earle School |
| Charnley, James, House |
| Charter Oak Schoolhouse |
| Chautauqua Auditorium |
| Chemical Laboratory |
| Chicago and Eastern Illinois Railroad Depot |
| Chicago and Northwestern Depot |
| Chicago and Northwestern Depot |
| Chicago and North Western Railroad Depot |
| Chicago and North Western Railway Power House |
| Chicago Beach Hotel |
| Chicago Bee Building |
| Chicago Board of Trade Building |
| Chicago, Burlington, and Quincy Railroad Depot |
| Chicago, Burlington, and Quincy Railroad Depot |
| Chicago, Burlington & Quincy Railroad Depot |
| Chicago, Burlington & Quincy Railroad Depot |
| Chicago, Burlington & Quincy Railroad Station |
| Chicago, Burlington, & Quincy Roundhouse and Locomotive Shop |
| Chicago Club |
| Chicago Federal Center |
| Chicago Great Western Railroad Depot |
| Chicago Harbor Lighthouse |
| Chicago, Milwaukee and St. Paul Railway Passenger Depot |
| Chicago Municipal Tuberculosis Sanitarium District |
| Chicago Public Library, Central Building |
| Chicago, Rock Island and Pacific Railroad Depot |
| Chicago Savings Bank Building |
| Chicago Telephone Company Kedzie Exchange |
| Chicago Varnish Company Building |
| Chicago Vocational School |
| Chick House |
| Childs, Robert A. and Mary, House |
| Chipman, Edith, House |
| Chipman, Edward, Public Library |
| Christ Church of Lower Kickapoo |
| Christ Episcopal Church |
| Christ Episcopal Church |
| Churchill, Richard, House |
| Church of Christ |
| Church of the Epiphany |
| Church of the Holy Family |
| Church of the St. Sava Serbian Orthodox Monastery |
| Churchville School |
| City and Town Hall |
| City Building |
| Clarke, Henry B., House |
| Clarksburg Schoolhouse |
| Clay County Courthouse |
| Clay County Jail |
| Clayson, George, House |
| Clayville Tavern |
| Clear Creek Meeting House |
| Cloud, Aaron G., House |
| Cloud, Chalon Guard and Emma Blades, House |
| Cloud State Bank |
| Clover Lawn |
| Cluever, Richard, House |
| Coca-Cola Bottling Company Building |
| Coca Cola Company Building |
| Coffeen, William and Helen, House |
| Coleman Hardware Company Building |
| Coles County Courthouse |
| Collins, Daniel Dove, House |
| Collinsville City Hall and Fire Station |
| Collinsville Masonic Temple Lodge #712 A.F. & A.M. |
| Collinsville Township High School |
| Colonnade Court |
| Colwell, E. B., and Company Department Store |
| Commercial House |
| Community House |
| Compton, Arthur H., House |
| Compton, Dr. Charles, House |
| Condit, Cortland, House |
| Condon Brothers and R.H. Shumway Building |
| Conger, J. Newton, House |
| Congress Theater |
| Connor House |
| Continental and Commercial National Bank |
| Conway Building |
| Cook County Criminal Court Building |
| Cook County Hospital Administration Building |
| Cook, John W., Hall |
| Cook Memorial Library |
| Coonley, Avery, House |
| Coonley, Avery, School |
| Copley, Col. Ira C., Mansion |
| Copley Hospital |
| Cornelia, The |
| Coronado |
| Country Tea Room |
| Count's House |
| Covell, Lucein Boneparte, House |
| Covent Hotel |
| Cox, George H., House |
| Craig and Estella Hazelwood House |
| Crane Company Building |
| Creamery Package Manufacturing Company Building |
Data from United States Park Service and Wikidata
