All - Constructed - 1920–1929
| Men's Gymnasium, University of Arizona |
| Mercado de las Carnes |
| Merced Lake Ranger Station |
| Merchants National Bank of Sacramento |
| Metropolitan Theatre |
| Meyer House |
| Miami-Biltmore Hotel |
| Micheel, Herman F., Gothic Arched-Roof Barn |
| Michigan-Lee Apartments |
| Michigan Theater Building |
| Middough Brothers-Insurance Exchange Building |
| Midgaard |
| Midland County Courthouse |
| Milford Rural Agricultural School |
| Millard House |
| Millard-McCarty House |
| Miller, L. D., Funeral Home |
| Miller, Marshall D., Boathouse |
| Million Dollar Theater |
| Mill Street-South Branch Raisin River Bridge |
| Milner Pass Road Camp Mess Hall and House |
| Milwaukee Breakwater Light |
| Milwaukee County Courthouse |
| Milwaukee County Dispensary and Emergency Hospital |
| Mine Creek Bridge |
| Missisquoi River Bridge |
| Mississippi River Bridge |
| Mogollon Baldy Lookout Cabin |
| Molyneux Chevrolet Company-Rockwood Fire Department Building |
| Monfils, Joseph, Farmstead |
| Montezuma Hotel |
| Montezuma Valley Irrigation Company Flume No. 6 |
| Montgomery Ward Building |
| Montgomery Ward Warehouse and Retail Store |
| Moore Public School Building |
| Moores Creek National Battlefield |
| Moore Store |
| Mopac Station |
| More Automobile Company Building |
| Moreauville High School |
| Morgan, David-Bronson, Earl A., House |
| Morgan Union Pacific Depot |
| Mormon Flat Dam |
| Morris Memorial Building |
| Morrison, Edward, House |
| Mosaic Templars State Temple |
| Motley Slough Bridge |
| Mountain Brook Estates Building |
| Mountaineer Hotel |
| Mountain States Telephone and Telegraph Company Building |
| Mount Baker Theatre |
| Mount Brown Fire Lookout |
| Mount Hope Bridge |
| Mount Rushmore National Memorial |
| Mount Shiloh Missionary Baptist Church |
| Mowich Lake Patrol Cabin |
| Mt. Prospect School for Boys |
| Mt. Sinai Baptist Church |
| Mt. Zion Baptist Church |
| Mullins Court |
| Murphy-Collins House |
| Murphy High School |
| Muscatine County Home Dairy Barn |
| Museum-Grotto Residence |
| Museum of Northern Arizona Exhibition Building |
| Muskegon YMCA Building |
| Mutual Building |
| Naniboujou Club Lodge |
| Narada Falls Bridge |
| Nash, Arthur C. and Mary S.A., House |
| Nashville, Chattanooga, and St. Louis Railway Office and Freight House |
| Nathan Warnick Apartments |
| National Biscuit Company Carton Making and Printing Plant |
| National Theater |
| National Town and Country Club |
| Navajo Steel Arch Highway Bridge |
| Naval Training Station |
| Nebel Knitting Mill, Former |
| Nectar Covered Bridge |
| Neillsville Masonic Temple Lodge No. 163 |
| Neosho River Bridge |
| Nevins Bridge |
| Newbern Hotel |
| Newbern Illinois Central Depot |
| Newell High School |
| New England Telephone and Telegraph Engineering Office |
| New Hampshire Savings Bank Building |
| New Heathman Hotel |
| New Hotel Carquinez |
| New Masonic Building and Oriental Theater |
| New Mexico Military Institute Summer Camp, Main Building |
| New Orleans Great Northern Railroad Passenger Depot |
| New Perry Hotel |
| New Sequoia Theater Building |
| Newton Centre Branch Library |
| Newtown Elementary School |
| New York Central Terminal |
| New York Life Building |
| New York Telephone Company Building |
| Niagara Falls School District Administration Building |
Data from United States Park Service and Wikidata
