All - Constructed - 1860–1869
| Leak-Chaffin-Browder House |
| Lee and Gordon Mill |
| Lee Chapel, Washington and Lee University |
| Lemont Central Grade School |
| Lewis, Ervin, House |
| Lewis-Williams House |
| Libby-Hill Block |
| Limerick Historic District |
| Lincoln High School |
| Lindenwood Cemetery |
| Lippitt, Gov. Henry, House |
| Lisle-Shields Town House |
| Little Red Schoolhouse |
| Little Rock National Cemetery |
| Lloyd and Henry Warehouse |
| Lobell, Adam, House |
| Logan, Thomas E., House |
| Londonderry Town House |
| Longwood |
| Loudon Park National Cemetery |
| Louisville Water Company Pumping Station |
| Lovejoy Bridge |
| Lower Pleasant Street District |
| Lubben, Henry, House, Smokehouse and Springhouse |
| Lucky Plantation House |
| Lyons, Horace G., House |
| Magnolia Manor |
| Main and Third Street Cluster |
| Manassas Battlefield Historic District (Boundary Increase) |
| Manatt, William, House |
| Mansfield Bridge |
| Marietta National Cemetery |
| Marion Township School District No. 3 |
| Marques de la Serna Bridge |
| McCartney, James H. and Mayetta (Degrush), House |
| McCollister, James, Farmstead |
| McCurtain, Edmund, House |
| McIntosh Log Church |
| McKibben, S. M., House |
| McKimmons, John, Barn |
| McKinley High School |
| McMahon House |
| McReynolds House |
| Mead, Alpheus, House |
| Meadow Grove Farm |
| Meadows, The |
| Mechanics Mill |
| Merion Cricket Club |
| Merriman, Wells E., House |
| Merritt, Samuel T., House |
| Methodist Episcopal Church of Hibernia |
| Metropolitan Savings Bank |
| Mill Rock School |
| Mills River Chapel |
| Minnesota Stoneware Company |
| Mitton, Samuel Crowthers, House |
| Monongahela Cemetery |
| Moore, Benjamin C., Mill |
| Moorehead Stagecoach Inn |
| Moore, William Alfred, House |
| Morrill Hall, Cornell University |
| Morrissey, Thomas and Anna, House |
| Morse-Scoville House |
| Morton, Asher, Farmstead |
| Mother Of God Roman Catholic Church |
| Mottley Family Farmstead |
| Mount Hope Miners' Church |
| Mt. Gilead Baptist Church |
| Mystic Dam |
| Mystic Water Works |
| Natchez National Cemetery |
| Navesink Light Station |
| Naylor House |
| Nevada Theatre |
| New Bern National Cemetery |
| Newberry, Milo Prentice, House |
| New Brighton Village Hall |
| Newcome, Daniel T., Double House |
| Newell-Johnson-Searle House |
| New England Conservatory of Music |
| New Hampton Pony Pratt Truss Bridge |
| New Haven Clock Company Factory |
| New Hill Historic District |
| Nichols, Capt. John P., House |
| Noble Block |
| Normand House |
| Northern Methodist Episcopal Church of Clarksville |
| North, Townsend, House |
| North Waterford Congregational Church |
| Oak Hill Cemetery |
| Oakslea Place |
| Octagon Hall |
| Ogden Union Station |
| O'Kelly, Berry, Historic District |
| Old Albany Schoolhouse |
| Old Cambridge Baptist Church |
| Old Dowlin Mill |
| Old East Paint Creek Lutheran Church |
| Old Indiana County Courthouse |
| Old Irontown |
Data from United States Park Service and Wikidata
