Maryland - Criteria: A (event)
| Brown, Jeremiah, House and Mill Site |
| Brown, Moses, House |
| Brown's Arcade |
| Brunswick Historic District |
| Bryantown Historic District |
| Buckeystown Historic District |
| Buck House |
| Buckingham House and Industrial School Complex |
| Buildings at 1601-1830 St. Paul Street and 12-20 E. Lafayette Street |
| Bullfrog Road Bridge |
| Burkittsville |
| Business and Government Historic District |
| Butchers Hill Historic District |
| Butler House |
| Cabin John Aqueduct |
| Callahan, John, House |
| Calloway, Thomas J., House |
| Calvert Hills Historic District |
| Cambridge Historic District, Wards I and III |
| Camp Greentop Historic District |
| Camp Misty Mount Historic District |
| Cannonball House |
| Canton Historic District |
| Canton House |
| Captain's Houses |
| Carderock Springs Historic District |
| Carousel at Glen Echo Park |
| Carroll County Almshouse and Farm |
| Carrollton Viaduct |
| Carson, Rachel, House |
| Casselman's Bridge, National Road |
| Cathedral Hill Historic District |
| Catoctin Furnace Historic District |
| Caves Valley Historic District |
| Cecil Apartments |
| Cecil's Mill Historic District |
| Cedarcroft Historic District |
| Cedar Grove |
| Cedar Park |
| Centreville Armory |
| Centreville Historic District |
| Chamber of Commerce Building |
| Chambers Park Log Cabin |
| Chance Boatyard |
| Chapel Hill Historic District |
| Chapline, William, House |
| Charlestown Historic District |
| Charles Village-Abell Historic District |
| Charlotte Hall Historic District |
| Chautauqua Tower |
| CHESAPEAKE BAY BROGAN MUSTANG |
| Chesapeake Beach Railway Station |
| CHESAPEAKE (lightship) |
| Chestertown Armory |
| Chestertown Railroad Station |
| Chesterville Brick House |
| Chestnut Ridge |
| Childs Residence |
| Chizuk Amuno Synagogue |
| Christ Church |
| Christ Church |
| Christ Church, Graveyard and Sexton's House |
| Christ Church Guilford |
| Christ Episcopal Church and Cemetery |
| Churchill Threatre-Community Building |
| Churchville Presbyterian Church |
| Citizens State Bank |
| City Hall |
| Clagett, Robert, Farm |
| CLARENCE CROCKETT |
| Clarksburg School |
| Clark's Conveniency |
| CLAUDE W. SOMERS |
| Clay's Hope |
| Clifton |
| Clifton School |
| Cloisters, The |
| Coca-Cola Baltimore Branch Factory |
| Coca-Cola Bottling Company of Baltimore Building |
| Cockey-Jamison-Hendrickson House and Store |
| Coldstream Homestead Montebello Historic District |
| College Heights Estates Historic District |
| College of Medicine of Maryland |
| College Park Airport |
| Colonial Annapolis Historic District |
| Colonial Theatre |
| Colora Meetinghouse |
| Commercial Credit Company Building |
| Compton Bassett |
| Concord |
| Content |
| Continental Trust Company Building |
| Cool Hollow Home |
| Corbett Historic District |
| Coventry Parish Ruins |
| Cove Point Lighthouse |
| Craighill Channel Lower Range Front Light Station |
| Craighill Channel Lower Range Rear Light Station |
| Crampton's Gap Historic District |
| Crisfield Armory |
Data from United States Park Service and Wikidata
