Connecticut - Area of significance: Commerce
| Aetna Diner |
| Alden Tavern Site |
| Ann Street Historic District |
| Armstrong, M. and Company Carriage Factory |
| Bacon, Jabez, House |
| Bank Street Historic District |
| Barns, Acors, House |
| Bigelow-Hartford Carpet Mills |
| Bill, Gurdon, Store |
| Bissell Tavern-Bissell's Stage House |
| Branchville Railroad Tenement |
| Brooks, Hervey, Pottery Shop and Kiln Site |
| Burritt Hotel |
| Camp, Moses, House |
| Cannondale Historic District |
| Carpenter House |
| Carpenter, Joseph, Silversmith Shop |
| Carroll Building |
| Central Village Historic District |
| Chapel Street Historic District |
| CHARLES W. MORGAN |
| CHRISTEEN (oyster sloop) |
| Colebrook Store |
| Commercial Trust Company Building |
| Danielson Main Street Historic District |
| Department Store Historic District |
| Downtown New Britain |
| Downtown Norwich Historic District |
| Downtown Seymour Historic District |
| Downtown Stamford Historic District |
| Downtown Torrington Historic District |
| Downtown Waterbury Historic District |
| Dwight Street Historic District |
| East Haddam Historic District |
| East Main Street Historic District |
| Elm Street Historic District |
| Elton Hotel |
| Enfield Canal |
| Farmington Canal Lock |
| Farmington Canal Lock No. 13 |
| Farmington Canal-New Haven and Northampton Canal |
| Florence Mill |
| Frisbie, Edward, Homestead |
| Glastonbury-Rock Hill Ferry Historic District |
| Goodwin Block |
| Gorton, William, Farm |
| Goshen Historic District |
| Hall-Benedict Drug Company Building |
| Hamden Bank & Trust Building |
| Harris, Jonathan Newton, House |
| Hebron Center Historic District |
| High Street Historic District |
| Hollister, Homestead, The |
| Home Woolen Company |
| Humphreys, Gen. David, House |
| Hunt, Dr. Chester, Office |
| Imperial Granum-Joseph Parker Buildings |
| Indian Hill Avenue Historic District |
| Lakeville Historic District |
| Lathrop, Dr. Joshua, House |
| Main Street Historic District |
| Main Street Historic District |
| Main Street Historic District |
| Main Street Historic District |
| Main Street Historic District No. 2 |
| Mansuy and Smith Automobile Showroom Building |
| Marlborough Tavern |
| Meeker's Hardware |
| Merritt Beach & Son Building |
| Middletown Upper Houses Historic District |
| Milford Point Hotel |
| Millington Green Historic District |
| Mixer Tavern |
| National Hall Historic District |
| New Milford Center Historic District |
| Ninth Square Historic District |
| Noank Historic District |
| North Cove Historic District |
| Old Riverton Inn |
| Old Wethersfield Historic District |
| Osbornedale |
| Oyster Point Historic District |
| Palmer, Capt. Nathaniel B., House |
| Peck Tavern |
| Pequabuck Bridge |
| Phelps, Arah, Inn |
| Pines Bridge Historic District |
| Pomeroy, Arthur G., House |
| Pond-Weed House |
| Poquetanuck Village Historic District |
| Post, Augustus, House |
| Pratt House |
| Pratt Street Historic District |
| Restmore |
| Schoverling, Carl F., Tobacco Warehouse |
| Seelye, Seth, House |
| Sharon Historic District |
| Simsbury Bank and Trust Company Building |
| Skee's Diner |
| South Main and Washington Streets Historic District |
Data from United States Park Service and Wikidata
