Built during 1890s

Newton Cottage Hospital Historic District (Middlesex County, Massachusetts)
Newton House (Clarke County, Georgia)
Newton Seymour Tubbs House (Custer County, South Dakota)
Newton Street Railway Carbarn (Middlesex County, Massachusetts)
Newtonville United Methodist Church (Albany County, New York)
Niagara Camp (Tuolumne County, California)
Niagara Falls Armory (Niagara County, New York)
Niblock--Yacovetta Terrace (Denver County, Colorado)
Nichelini Winery (Napa County, California)
Nicholas County Courthouse (Nicholas County, West Virginia)
Nicholas Koester Building (Scott County, Iowa)
Nicholas O. Walden House (Clackamas County, Oregon)
Nichols Memorial Library (Rockingham County, New Hampshire)
Nichols, John F., House (Middlesex County, Massachusetts)
Nicolet Public School (Outagamie County, Wisconsin)
Romanesque Revival school designed by local architect, Phillip Dean
Niels Petersen House (Maricopa County, Arizona)
Nielsen Farm (Lincoln County, Kansas)
Niles, Louville V., House (Middlesex County, Massachusetts)
Niles, Louville, House (Middlesex County, Massachusetts)
Nine Hearths (Warren County, Kentucky)
Ninth Avenue Historic District (Spokane County, Washington)
Ninth District Lighthouse Depot (Berrien County, Michigan)
Niotaze Methodist Episcopal Church (Chautauqua County, Kansas)
No. 12 School (Crawford County, Arkansas)
No. 206 Hall of Tell City Lodge IOOF (Perry County, Indiana)
Noah Edward Edgerton House (Johnston County, North Carolina)
Noah Moore House (Clarke County, Mississippi)
Noble Horse Barn (Owyhee County, Idaho)
Noblesville Milling Company Mill (Hamilton County, Indiana)
Former industrial building now converted to residential housing
Nolin Banking Company (Hardin County, Kentucky)
Nolte--Rooney House (Brewster County, Texas)
Nonnenmacher Bakery (Calhoun County, Alabama)
Nook, The (York County, Pennsylvania)
Norburn Terrace (Wake County, North Carolina)
Nordre Trefoldegheds Menigheds (Walsh County, North Dakota)
NORMAN (shipwreck) (Presque Isle County, Michigan)
Norman Brimhall House (Navajo County, Arizona)
Norman No. 1 Oil Well Site (Wilson County, Kansas)
Normandie Apartments (Douglas County, Nebraska)
North Abington Depot (Plymouth County, Massachusetts)
North Baltimore Town Hall (Wood County, Ohio)
North Brentwood Historic District (Prince George's County, Maryland)
North Broad Street Historic District (Essex County, New Jersey)
North Carolina Executive Mansion (Wake County, North Carolina)
North Elm Street Historic District (Hempstead County, Arkansas)
North Ghent (Norfolk, Virginia)
North Head Lighthouse (Pacific County, Washington)
65' Conical Lighthouse tower built in 1898
North Jay Grange Store (Franklin County, Maine)
North Long Branch School--Primary No. 3 (Monmouth County, New Jersey)
North Main Street Historic District (Davie County, North Carolina)
North Mankato Public School (Nicollet County, Minnesota)
North Pemberton Railroad Station (Burlington County, New Jersey)
North Plant City Residential District (Hillsborough County, Florida)
North Third Avenue Historic District (Chatham County, North Carolina)
North Tracy Avenue Historic District (Gallatin County, Montana)
Northampton Lumber Company Historic District (Northampton County, Virginia)
Northern District Police Station (Baltimore, Maryland)
Northern National Bank (Philadelphia County, Pennsylvania)
Northern Pacific Depot (Pine County, Minnesota)
Northern Pacific Office Building (Pierce County, Washington)
Northern Pacific Railway Depot (Cass County, North Dakota)
Northern Pacific Railway Depot (Morrison County, Minnesota)
Northrup House (Allen County, Kansas)
Northside United Methodist Church (Hamilton County, Ohio)
Norton House (Yuma County, Arizona)
Norwalk River Railroad Bridge (Fairfield County, Connecticut)
Norway Historic District (Oxford County, Maine)
Norwell Residence (Hamilton County, Ohio)
Norwood-TWL Building (Pike County, Mississippi)
Notre Dame de Chicago (Cook County, Illinois)
Notre Dame School (Bristol County, Massachusetts)
Noyes, J.A., House (Middlesex County, Massachusetts)
Nuckolls County Courthouse (Nuckolls County, Nebraska)
Nugent Home for Baptists (Philadelphia County, Pennsylvania)
O'Bannon Homestead (Cass County, Missouri)
O'Brien, Richard, Three-Decker (Worcester County, Massachusetts)
O'Connor House (Pembina County, North Dakota)
O'Connor--Proctor Building (Victoria County, Texas)
O'Hara Waltham Dial Company (Middlesex County, Massachusetts)
O. B. Sims House (Ellis County, Texas)
O. L. and Josephine Morgan House (Jefferson County, Washington)
Oak Dell (Morris County, New Jersey)
Oak Grove Methodist Church (Meigs County, Tennessee)
Oak Knitting Company (Onondaga County, New York)
Oak Knoll (Middlesex County, Massachusetts)
Oak Ridge Military Academy Historic District (Guilford County, North Carolina)
Oak Square School (Suffolk County, Massachusetts)
Oak Street School (Androscoggin County, Maine)
Oakdale Public School (Allegheny County, Pennsylvania)
Oakdene (Staunton, Virginia)
Oakes Estate (Essex County, New Jersey)
Oakesdale City Hall (Whitman County, Washington)
Oakland (Hanover County, Virginia)
Oakland Block (Whatcom County, Washington)
Oakland Public School (Allegheny County, Pennsylvania)
Oaks, The (Montgomery County, Virginia)
Oakwood Cemetery Chapel (Summit County, Ohio)
Ocean City Tenth Street Station (Cape May County, New Jersey)
Ochsner Hospital (La Plata County, Colorado)
Ocoee Christian Church (Orange County, Florida)
Oconomowoc Depot (Waukesha County, Wisconsin)
Oconto County Courthouse (Oconto County, Wisconsin)
Odd Fellows Building (Deuel County, South Dakota)
Odd Fellows Building (Daviess County, Kentucky)
Odd Fellows Hall (Baltimore, Maryland)
Odd Fellows Hall (Sheridan County, Wyoming)
Odd Fellows' Home (Worcester County, Massachusetts)
demolished in 2014
Officers' Row Historic District (Kitsap County, Washington)
Ogdensburg Armory (St. Lawrence County, New York)
Ogle County Courthouse (Ogle County, Illinois)
Romanesque Revival, red brick structure designed by George O. Garnsey
Oglesby School (Davidson County, Tennessee)
Ogunquit Memorial Library (York County, Maine)
Ohio Street Bridge (Vanderburgh County, Indiana)
Through truss bridge over Pigeon Creek on Ohio Street
Oil Springs Methodist Church (Johnson County, Kentucky)
Old Akron Post Office (Summit County, Ohio)
Old Arkansas City High School (Cowley County, Kansas)
Old Ashland Post Office (Ashland County, Wisconsin)
Old Bag Factory (Elkhart County, Indiana)
Brick factory building and brick power house.
Old Barnhill Building (Moniteau County, Missouri)
Old Botany Building (Ingham County, Michigan)
Academic Building on Michigan State University North Campus
Old Brazoria County Courthouse (Brazoria County, Texas)
Old Brooklyn Fire Headquarters (Kings County, New York)
Old California City Hall and Fire Station (Moniteau County, Missouri)
Old Camden Post Office (Ouachita County, Arkansas)
Old Capitol Building (Thurston County, Washington)
Old Carriage Barn (Richland County, Ohio)
Old Central Fire Station (Berkshire County, Massachusetts)
Old Central High School (Berkshire County, Massachusetts)
Old City Hall (Pierce County, Washington)
Old City Road Stone Arch Bridge (Herkimer County, New York)
Stone arch bridge over City Brook on Old City Road
Old Colony Buildings (Cook County, Illinois)
Old Courthouse (Buena Vista, Virginia)
Old Cranbury School (Middlesex County, New Jersey)
Old DeKalb County Courthouse (DeKalb County, Georgia)
Old Elbert County Jail (Elbert County, Georgia)
Old Federal Building (St. Landry Parish, Louisiana)
Old Federal Courts Building (Ramsey County, Minnesota)
Old Federal Reserve Bank (Philadelphia County, Pennsylvania)
Old Fentress County Jail (Fentress County, Tennessee)
Old Finnish Lutheran Church (Lawrence County, South Dakota)
Old Fire Engine House (Penobscot County, Maine)
Old Fort Church (New Castle County, Delaware)
Old Frankfort City Jail (Marshall County, Kansas)
Old Frankfort Stone High School (Clinton County, Indiana)
Old Fresno Water Tower (Fresno County, California)
Old German Consulate (Jefferson County, Washington)
Old Grandin Library (Hunterdon County, New Jersey)
Old Grolier Club (New York County, New York)
Old Hamilton County Jail (Hamilton County, Florida)
Old Haralson County Courthouse (Haralson County, Georgia)
Old Harbor U.S. Life Saving Station (Barnstable County, Massachusetts)
Old Iron County Courthouse (Iron County, Wisconsin)
Old Jail (Wilkes County, Georgia)
Old Katy Bridge (Geary County, Kansas)
Through truss bridge over Lyon Creek on Otter Creek Road, just southeast of Wreford
Old Lafayette City Hall (Lafayette Parish, Louisiana)
Old Lafayette County Courthouse (Lafayette County, Florida)
Old Las Vegas City Hall (San Miguel County, New Mexico)
Old Library Building (Kankakee County, Illinois)
Library for over 100 years now serving as the city hall
Old Livery Stable (El Paso County, Colorado)
Old Log Church (Warren County, Kentucky)
Old Lone Star Brewery (Bexar County, Texas)
Old Main (Coles County, Illinois)
Old Main (Pierce County, Washington)
Old Main (Albany County, Wyoming)
Old Main and Science Buildings (Iron County, Utah)
Old Main Building (Cook County, Illinois)
Old Main, Western Washington State College (Whatcom County, Washington)
Old Medford High School (Middlesex County, Massachusetts)
Old Middletown High School (Middlesex County, Connecticut)
Old Mill at Montauk State Park (Dent County, Missouri)
Old Miller Hospital (Shiawassee County, Michigan)
Old Morrison Mill (White County, Illinois)
Old Norfolk City Hall (Norfolk, Virginia)
Old North Tower, Central State College (Oklahoma County, Oklahoma)
Old Pathology Building (Marion County, Indiana)
Old Peace Lutheran Church (Franklin County, Ohio)
Old Post Office (Hamilton County, Tennessee)
Old Post Office (East Baton Rouge Parish, Louisiana)
Old Post Office and Clock Tower (Washington, District of Columbia)
Old Post Office Building (Plymouth County, Massachusetts)