Commercial building

Morristown Store (Maricopa County, Arizona)
Morrow and Sinnige Nabers Building (Jefferson County, Alabama)
Morse & Co. Office Building (Penobscot County, Maine)
Morse Hardware Company Building (Whatcom County, Washington)
Morton Brothers Grocery (Harris County, Texas)
Morton Building (Clarke County, Georgia)
Morton Cook Building (Okmulgee County, Oklahoma)
Moses Little Tavern (Washington County, Pennsylvania)
Motor Mart Building (Woodbury County, Iowa)
Motor Service Company (Pennington County, South Dakota)
Mott Drug Store (Portage County, Ohio)
Mott Willis Store (Charlotte County, Florida)
Mottman Building (Thurston County, Washington)
Mound Bayou Bank (Bolivar County, Mississippi)
Mount Ida Cities Service Filling Station (Montgomery County, Arkansas)
Mount Morris Bank (New York County, New York)
Mountain Brook Estates Building (Jefferson County, Alabama)
Moyers Buildings (Owsley County, Kentucky)
Mr. B's BBQ (El Paso County, Colorado)
Mr. Powdrell's Original Barbecue (Bernalillo County, New Mexico)
Mrs. Young Building (Washington County, Arkansas)
Muller's Department Store (Calcasieu Parish, Louisiana)
Mulvenon Building (Yavapai County, Arizona)
Mulvey Mercantile (Canadian County, Oklahoma)
Munday's Landing (Woodford County, Kentucky)
Munger and Company White Store (Madison County, Iowa)
Munger Moss Motel (Laclede County, Missouri)
Municipal Warehouse No. 1 (Los Angeles County, California)
Munroe Building (Norfolk County, Massachusetts)
Munson Diner (Sullivan County, New York)
Muscle Shoals Sound Studio (Colbert County, Alabama)
Musgrove Block (Essex County, Massachusetts)
Mutual Aid Union Building (Benton County, Arkansas)
Mutual Benefit Life Insurance Company (Essex County, New Jersey)
Mutual Building (Ingham County, Michigan)
Mutual Savings Bank Building (San Francisco County, California)
Myers Block--Home Company Building (Ashland County, Ohio)
Myrtle Bank (Adams County, Mississippi)
Myrtle Grove (Talbot County, Maryland)
N. A. Jacobsen Building (Payette County, Idaho)
N. E. Dickerson Store (Johnson County, Arkansas)
N. P. Smith Pioneer Hardware Store (Deschutes County, Oregon)
N. Snellenburg Company Department Store Warehouse (Philadelphia County, Pennsylvania)
Nallin Farm Springhouse and Bank Barn (Frederick County, Maryland)
Nampa Department Store (Canyon County, Idaho)
Nance-Major House and Store (Charles City County, Virginia)
Nancy's Little Giant Diner (Clinton County, Ohio)
Naniboujou Club Lodge (Cook County, Minnesota)
Nansen Store (Miner County, South Dakota)
Napa Opera House (Napa County, California)
Napoleon State Bank (Ripley County, Indiana)
Narcissa D-X Gas Station (Ottawa County, Oklahoma)
Nashville Arcade (Davidson County, Tennessee)
Nathan's Department Store (Cambria County, Pennsylvania)
Nathaniel West Buildings (Multnomah County, Oregon)
National American Bank Building (Orleans Parish, Louisiana)
National Bank of Ashland (Saunders County, Nebraska)
National Bank of Coatesville Building (Chester County, Pennsylvania)
National Bank of Commerce Building (Greene County, Arkansas)
National Bank of Commerce Building (Jackson County, Missouri)
National Bank of North Philadelphia (Philadelphia County, Pennsylvania)
National Bank of Rolla Building (Phelps County, Missouri)
Four story corner business building
National Bank of San Mateo (San Mateo County, California)
National Bank of Tacoma (Pierce County, Washington)
National Bank of Washington, Washington Branch (Washington, District of Columbia)
National Bank of Whittier Building (Los Angeles County, California)
National Brewing Company (Baltimore, Maryland)
National Building (King County, Washington)
National City Bank (New York County, New York)
National City Bank (Vanderburgh County, Indiana)
National Company Building (Monroe County, New York)
National Farmers' Bank (Steele County, Minnesota)
The most beautiful of Louis Sullivan's "Jewel Box" bank designs.
National Fuel Company Store (Boulder County, Colorado)
National Loan and Exchange Bank Building (Richland County, South Carolina)
National Metropolitan Bank Building (Washington, District of Columbia)
National Saving And Trust Company (Washington, District of Columbia)
National State Bank (Camden County, New Jersey)
National State Bank (Henry County, Iowa)
National State Bank Building (Rensselaer County, New York)
National Transit Building (Venango County, Pennsylvania)
National Union Building (Washington, District of Columbia)
National Valley Bank (Staunton, Virginia)
Navarre-Anderson Trading Post (Monroe County, Michigan)
Neal and Dixon's Warehouse (Marion County, South Carolina)
Neal Clothing (Allen County, Ohio)
Nebraska Telephone Company Building (Lancaster County, Nebraska)
Negaunee State Bank Building (Marquette County, Michigan)
Neil P. Anderson Building (Tarrant County, Texas)
Nelson E. Fisher House-High Banks (Iron County, Michigan)
Nelson--Kirby House (Shelby County, Tennessee)
Ness County Bank (Ness County, Kansas)
Nester House (Perry County, Indiana)
Netter--Ullman Building (Greene County, Missouri)
Neusteter Building (Denver County, Colorado)
New Baltimore Inn (Stark County, Ohio)
New England Building (Cuyahoga County, Ohio)
New England Telephone Building (Norfolk County, Massachusetts)
New Enterprise Tobacco Warehouse (Jefferson County, Kentucky)
New Era Building (Jackson County, Iowa)
New Hampshire Bank Building (Rockingham County, New Hampshire)
New Hampshire Savings Bank Building (Merrimack County, New Hampshire)
New Jersey Bell Headquarters Building (Essex County, New Jersey)
New Jersey Safe Deposit and Trust Company (Camden County, New Jersey)
New Orleans Cotton Exchange Building (Orleans Parish, Louisiana)
New Richmond News Building (St. Croix County, Wisconsin)
New River Company General Office Building (Fayette County, West Virginia)
New River Inn (Broward County, Florida)
New York Block (Douglas County, Wisconsin)
New York Cotton Exchange (New York County, New York)
New York Evening Post Building (New York County, New York)
New York Life Building (Jackson County, Missouri)
New York Life Building (New York County, New York)
New York Mutual Life Insurance Company Building (Philadelphia County, Pennsylvania)
New York Savings Bank (New York County, New York)
New York Stock Exchange (New York County, New York)
Newark Opera House (New Castle County, Delaware)
Newel K. Whitney Store (Lake County, Ohio)
Newman Block (La Plata County, Colorado)
Newman Brothers Building (Jasper County, Missouri)
Newport National Bank (New Castle County, Delaware)
Newspaper Row (Suffolk County, Massachusetts)
Nicholas County Bank (Nicholas County, West Virginia)
Nick's Hamburger Shop (Brookings County, South Dakota)
Nickels Arcade (Washtenaw County, Michigan)
Nicollet County Bank (Nicollet County, Minnesota)
Niece Brothers' Store (Custer County, Idaho)
Niolon Building (Lauderdale County, Mississippi)
Nisbett Building (Mecosta County, Michigan)
Nissen Building (Forsyth County, North Carolina)
No. 8 Thomas Street Building (New York County, New York)
Noah Bryan Store (Searcy County, Arkansas)
Nob Hill Business Center (Bernalillo County, New Mexico)
Nolin Banking Company (Hardin County, Kentucky)
Nonnenmacher Bakery (Calhoun County, Alabama)
Nooter Corporation Building (St. Louis, Missouri)
Nora Store (Union County, South Dakota)
Norseland General Store (Nicollet County, Minnesota)
North Bank Depot Buildings (Multnomah County, Oregon)
North Conway 5 and 10 Cent Store (Carroll County, New Hampshire)
North Wisconsin Lumber Company Office (Sawyer County, Wisconsin)
Former business office repurposed as a bar/restaurant
Northern Bank and Trust Building (King County, Washington)
Northern Bank of Kentucky (Kenton County, Kentucky)
Northern Block (Douglas County, Wisconsin)
Northern Life Tower (King County, Washington)
Northern National Bank (Philadelphia County, Pennsylvania)
Northern Pacific Office Building (Pierce County, Washington)
Northern Pacific Warehouse (Sanders County, Montana)
Northern Saving Fund and Safe Deposit Company (Philadelphia County, Pennsylvania)
Northwestern Improvement Company Store (Kittitas County, Washington)
Northwestern National Bank Building (Multnomah County, Oregon)
Norton--Johnson Buick Company (Oklahoma County, Oklahoma)
Norway Center Store (Lincoln County, South Dakota)
Noxon Bank Building (Saratoga County, New York)
O Street Market (Washington, District of Columbia)
O'Connor--Proctor Building (Victoria County, Texas)
O'Hanlon Building (Forsyth County, North Carolina)
O'Kane Building (Deschutes County, Oregon)
O'Neil Lumber Company Office (Flathead County, Montana)
O'Neil's Department Store (Summit County, Ohio)
O'Neill Brothers Building (Elmore County, Idaho)
O'Rourke's Diner (Middlesex County, Connecticut)
O. E. Woods Lumber Co. Building (Rogers County, Oklahoma)
O. G. Anderson & Co. Store (Lyon County, Minnesota)
O. K. Market (Saunders County, Nebraska)
O. T. Bassett Tower (El Paso County, Texas)
Oakes National Bank Block (Dickey County, North Dakota)
Oakhurst Diner (Dutchess County, New York)
Re-opened as the Oakhurst Diner in 2010.
Oakville Grocery (Napa County, California)
Oasis Lounge (Yavapai County, Arizona)
Oates Building (Polk County, Florida)
Oatman Drug Company Building (Mohave County, Arizona)
Oatman Filling Station (Eau Claire County, Wisconsin)
Occidental Life Building (Bernalillo County, New Mexico)
Occidental Life Insurance Company Building (Wake County, North Carolina)
Ocean House (Westchester County, New York)
A Bixler Manufacturing Co. diner converted to a restaurant.
Odd Fellows Block (Union County, Iowa)
Odd Fellows Building (Tehama County, California)
Odd Fellows Building (Pike County, Kentucky)
Odd Fellows Building (Daviess County, Kentucky)
Odd Fellows Lodge (Wayne County, North Carolina)
Odd Fellows Temple (Fayette County, Kentucky)
Odd Fellows Temple (Columbiana County, Ohio)
Oddfellows Building (Middlesex County, Massachusetts)
Oddfellows House (Fairbanks North Star Borough, Alaska)