New York - Criteria: A (event)
| Church of the Immaculate Conception and Clergy Houses |
| Church of the Transfiguration and Rectory |
| Church Street-Congress Street Historic District |
| Church Street Historic District |
| Church Street Historic District |
| Citizens National Bank |
| City Hall |
| City Hall Subway Station (IRT) |
| City Pier A |
| Civic Club |
| Clapham-Stern House |
| Claremont Stables |
| Clarendon Stone Store |
| Clare Town Hall |
| Clark-Dearstyne-Miller Inn |
| Clarke, Edwin W. and Charlotte, House |
| Clark Farm Complex |
| Clark, Hulet, Farmstead |
| Clark, Peyton, Cottage |
| Clarkson Chapel |
| Clarkson-Knowles Cottage |
| Clark, Starr, Tin Shop |
| Clarksville Elementary School |
| Clermont Academy |
| Cleveland, Ephraim, House |
| Cliffside |
| Clifton |
| Clifton Park Center Baptist Church and Cemetery |
| Clifton Park Hotel |
| Clifton Springs Sanitarium Historic District |
| Clinton Avenue Historic District |
| Clinton-Columbia Historic District |
| Clinton Corners Friends Church |
| Clinton House |
| Clinton-Rosekrans Law Building |
| Clinton Village Historic District |
| Closter Road-Oak Tree Road Historic District |
| Clymer District School No. 5 |
| Cobblestone Railroad Pumphouse |
| Cobble Villa |
| Cobleskill Historic District |
| Cochecton Railroad Station |
| Cock-Cornelius House |
| Coeymans, Ariaanje, House |
| Coeymans-Bronck Stone House |
| Cohen, H. C., Company Building-Andrews Building |
| Colbath Cottage |
| Cold Brook Feed Mill |
| Colden Family Cemetery |
| Colden Mansion Ruins |
| Cold Spring Harbor Beach Club |
| Cold Spring Harbor Fire District Hook and Ladder Company Building |
| Cold Spring Harbor Laboratory Historic District |
| Cold Spring Harbor Library |
| Cold Spring Historic District |
| Cold Springs Cemetery |
| Coleman Station Historic District |
| Coletti-Rowland-Agan Farmstead |
| Collingwood Opera House and Office Building |
| Collinsville Cemetery |
| Colonial Flats and Annex |
| Colored Musicians Club |
| COLUMBIA (steamer) |
| Columbia Turnpike East Tollhouse |
| Columbia Turnpike-West Tollhouse |
| Columbus Monument |
| Commack Methodist Church and Cemetery |
| Common School 32 |
| Common School No. 10 |
| Community of True Inspiration Residence |
| Community Place |
| Community Theatre |
| Comstock Hall |
| Comstock, Nathan, Jr., House |
| Comstock, Zephnia, Farmhouse |
| Conant, Austin R., House |
| Concordia Cemetery |
| Concourse Yard Entry Buildings |
| Concourse Yard Substation |
| Concrete-Central Elevator |
| Coney Island Yard Electric Motor Repair Shop |
| Conference House |
| Congregation Ahavas Achim Anshi Austria |
| Congregation Beth Abraham |
| Congregation Bnai Israel Synagogue |
| Congregation B'nai Jeshurun Synagogue and Community House |
| Congregation Chevra Linath Hazedeck |
| Congregation Ohab Zedek |
| Congregation Shaare Zedek of Harlem |
| Congregation Tifereth Israel |
| Congregation Tifereth Israel |
| Congregation Tifereth Israel Synagogue |
| Congregation Tifereth Yehuda Veyisroel |
| Conklin, David, House |
| Conklin Farm |
| Conklin Town Hall |
| Connecticut Street Armory |
| Connors, William, Paint Manufacturing Company Building |
| Control House on 72nd Street |
| Coolidge Stores Building |
Data from United States Park Service and Wikidata
