All - Constructed - 1910–1919
| Carter County Courthouse |
| Casa del Gavilan |
| Casa Dr. Bailey K. Ashford |
| Casaus, Jesus M., House |
| Casino Theatre |
| Castleman, John B., Monument |
| Cathedral of the Most Blessed Sacrament |
| Catt, Carrie Chapman, House |
| C B & Q Holdrege Depot |
| C B & Q Passenger Depot |
| Cedar Rapids Central Fire Station |
| Cedar Snags |
| Central Avenue Historic District |
| Central Building, Public Library |
| Central Embarcadero Piers Historic District |
| Central Fire Station |
| Central High School |
| Central High School |
| Centralia Union Depot |
| Central Library |
| Central Library (Indianapolis-Marion County Public Library) |
| Central Park Theater |
| Central Steam Heat Plant |
| Central Warehouse |
| Central Wisconsin State Fair Round Barn |
| Central YMCA |
| Cermak, Anton, House |
| Chambers Street Subway Station (Dual System BMT) |
| Chandler High School |
| Chanute Field Historic District |
| Chapel of St. Anne |
| Charles River Basin Historic District |
| Charlton Leland |
| Charlton Mill |
| Chase, Charles F. and and Ruth, House |
| Chatham Southern Railway Depot |
| Chaves County Courthouse |
| Cheesman, Morton A., House |
| Cheoah Hydroelectric Development |
| Cherbourg Round Barn |
| Cherrydale Volunteer Fire House |
| Cherry Grove Baptist Church Schoolhouse |
| Cherry Hotel |
| Cherryvale Carnegie Free Library |
| Chicago and Northwestern Depot |
| Chicago, Burlington & Quincy Railroad Depot |
| Chicago, Milwaukee, St. Paul and Pacific Railroad Depot |
| Chicago, St. Paul, Minneapolis, and Omaha Railway Bridge |
| Chicken Creek Bridge |
| Childs, Mayor Edwin O., House |
| Chipman, Edward, Public Library |
| Chivers, Thomas, House |
| Church Farm School Historic District |
| Church of Saints Peter and Paul Complex |
| Church of St. Agnes-Catholic |
| Church of St. Joseph (Catholic) |
| Church of the Incarnation and Rectory |
| Church, William L., House |
| Citizens National Bank |
| Citizens National Bank Building |
| City Island Ball Park |
| City Line Avenue Bridge |
| City of Roanoke Fire Station No. 5 |
| City of Waterloo Carousel |
| City Park Golf |
| City Waterway Bridge |
| Clarke, James F., House |
| Clark House |
| Clarkston Public Library |
| CLAUDE W. SOMERS |
| Clay Center Carnegie Library |
| Clearwater Evangelical Lutheran Church |
| Clemens Automobile Company Building |
| Clemens Ranchhouse |
| Cleveland East Pierhead Light |
| Cloverfields |
| Clover Hotel |
| Cluever, Richard, House |
| Coates House |
| Coffeyville Carnegie Public Library Building |
| Coke, J. S., Building |
| Coleman, George L., Sr., House |
| Coleman-Scott House |
| Colfax Municipal Building |
| College View Public Library |
| Collins, William, House |
| Colman Automotive Building |
| Colman Park & Dose Terrace Stairs |
| Colonial Apartments |
| Colonial Hotel |
| Colonials Club House |
| Colonial Theatre Complex |
| Columbia Covered Bridge |
| Columbus Public Carnegie Library |
| Columbus Public Library |
| Commerce Block |
| Commons, John R., House |
| Community House, First Congregational Church |
| Compton, Arthur H., House |
| Comstock Hall |
Data from United States Park Service and Wikidata
