District of Columbia - Area of significance: Architecture
| Hampshire Garden Apartment Buildings |
| Harbour Square |
| Hardy, Rose Lees, School |
| Harewood Lodge |
| Harris & Ewing Photographic Studio |
| Harrison Apartment Building |
| Haw, John Stoddert, House |
| Healy Building, Georgetown University |
| Hebrew Home for the Aged and Jewish Social Service Agency |
| Hecht Company Warehouse |
| Heurich, Christian, Mansion |
| Heurich-Parks House |
| Hibbs, W. B., and Company Building |
| Highlands, The |
| Hillandale-Main Residence and Gatehouse |
| Hill Building |
| Holt House |
| Holy Redeemer College |
| Holzbeierlein Bakery |
| Homestead Apartments, The |
| Hotel Washington |
| House at 2437 Fifteenth Street, NW |
| House of Mercy |
| Hubert H. Humphrey Building |
| Immaculata Seminary Historic District |
| Immaculate Conception Church |
| Indonesian Embassy |
| Ingleside |
| Interior Department Offices |
| Janney Elementary School |
| Japanese Embassy |
| Jefferson Apartment Building |
| Jesse Reno School |
| Jost-Kuhn House |
| Kalorama Triangle Historic District |
| Kennedy-Warren Apartment Building |
| Keystone, The |
| King, Martin Luther, Memorial Library |
| Lafayette Apartment Building |
| Lafayette Elementary School |
| Langston, John Mercer, School |
| Langston Terrace Dwellings |
| Lansburgh, Julius, Furniture Co., Inc. |
| Law, Thomas, House |
| LeDroit Park Historic District |
| Lenthall Houses |
| Lewis, Edward Simon, House |
| Lexington, The |
| Lightfoot, George M., House |
| Lincoln Industrial Mission-Lincoln Memorial Congregational Church |
| Lincoln Memorial |
| Lincoln Theatre |
| Lindens, The |
| Lisner Auditorium |
| Lockkeeper's House, C & O Canal Extension |
| Logan Circle Historic District |
| Lothrop Mansion |
| Lucy Diggs Slowe Elementary School |
| Luther Place Memorial Church |
| Luzon Apartment Building |
| MacFarland Junior High School |
| Macfeely, Gen. Robert, House |
| Main Gate, Washington Navy Yard |
| Main Sewerage Pumping Station, District of Columbia |
| Manhattan Laundry |
| Mansion at 2401 15th St., NW. |
| Masonic Temple |
| Massachusetts Avenue Historic District |
| Maycroft, The |
| Mayflower Hotel |
| McCormick Apartments |
| McLachlen Building |
| McMillan Park Reservoir Historic District |
| Meeting House of the Friends Meeting of Washington |
| Meridian Hill Historic District |
| Meridian Hill Park |
| Meridian House |
| Meridian Manor |
| Meridian Mansions |
| Metropolitan African Methodist Episcopal Church |
| Metropolitan Apartments |
| Metropolitan Club |
| Military Road School |
| Milton Hall |
| Miner Normal School |
| Moran Building |
| Morrison and Clark Houses |
| Morris Residence |
| Mount Pleasant Historic District |
| Mount Vernon Square Historic District |
| Mount Vernon Triangle Historic District |
| Mount Vernon West Historic District |
| Mount Zion United Methodist Church |
| Mullett Rowhouses |
| Munson Hall |
| Myrene Apartment Building |
| Nathaniel Parker Gage School |
| National Academy of Sciences |
| National Archives |
| National Bank of Washington, Washington Branch |
Data from United States Park Service and Wikidata
