Moore House (Caswell County, North Carolina)
Moore Potato House (Sussex County, Delaware)
Moore--Hancock Farmstead (Travis County, Texas)
Moose River Congregational Church (Somerset County, Maine)
Moran Building (Washington, District of Columbia)
Morehead Hill Historic District (Durham County, North Carolina)
Morehead State University (Rowan County, Kentucky)
Morgan City City Hall and Courthouse (St. Mary Parish, Louisiana)
Morgan County Courthouse (Morgan County, Missouri)
Morgan County Courthouse (Morgan County, Indiana)
Morgan's Mill (Transylvania County, North Carolina)
Morgantown Historic District (Fauquier County, Virginia)
Morris County Courthouse (Morris County, New Jersey)
Morris Roberts Store (Gooding County, Idaho)
Morris--Lull Farm (Otsego County, New York)
Morrison and Clark Houses (Washington, District of Columbia)
Morrison House (Madison County, Kentucky)
Morrisville Historic District (Lamoille County, Vermont)
Morven (Fauquier County, Virginia)
Moses McKay House (Warren County, Ohio)
Mott Drug Store (Portage County, Ohio)
Mount Airy (Bedford County, Virginia)
Mount Carmel A.M.E. Zion Campground (Lancaster County, South Carolina)
Mount Hope (Fauquier County, Virginia)
Mount Jackson Historic District (Shenandoah County, Virginia)
Mount Nebo Baptist Church (Cooper County, Missouri)
Mount Olive High School (Former) (Wayne County, North Carolina)
Mount Pleasant Historic District (Banks County, Georgia)
Mount Vernon A.M.E. Church (Monroe County, Kentucky)
Mount Vernon Springs Historic District (Chatham County, North Carolina)
Mount Welcome (Lincoln County, North Carolina)
Mount Zion Church (Benton County, Tennessee)
Mount Zion Methodist Episcopal Church South (Lawrence County, Tennessee)
Mount Zion Presbyterian Church (Muskingum County, Ohio)
Mountain Glen (Bland County, Virginia)
Moyers Buildings (Owsley County, Kentucky)
Mrs. William R. Reding House (Bastrop County, Texas)
Mt. Bleak--Skye Farm (030-0283) (Fauquier County, Virginia)
Mt. Olive Methodist Episcopal Church (Loudoun County, Virginia)
Mt. Pleasant Methodist Church (Lowndes County, Mississippi)
Mt. Sidney Historic District (Augusta County, Virginia)
Mulberry Grove (Rockbridge County, Virginia)
Municipal Building (Hamilton County, Tennessee)
Munson Building (Buchanan County, Iowa)
Murray County Courthouse (Murray County, Georgia)
Brick two story courthouse
Mustoe House (Bath County, Virginia)
Mylius--Eaton House (Woodbury County, Iowa)
Myrick's Mill (Twiggs County, Georgia)
Myrick-Yeates-Vaughan House (Hertford County, North Carolina)
Mystic Theatre (Slope County, North Dakota)
Nails Creek Historic District (Banks County, Georgia)
Nance-Major House and Store (Charles City County, Virginia)
Natchez Street Historic District (Williamson County, Tennessee)
National Campground (Loudon County, Tennessee)
National Theater (Richmond, Virginia)
Nealy Gordon Farm (Montgomery County, Virginia)
Nebgen School (Gillespie County, Texas)
Neff Round Barn (Centre County, Pennsylvania)
Neils Red Covered Bridge (Greene County, Pennsylvania)
Nelson County Courthouse (Nelson County, Virginia)
Nelsonville Historic District (Athens County, Ohio)
Netherland Tait House (Lewis County, Tennessee)
Neville House (Richmond County, New York)
New Baltimore Historic District (Fauquier County, Virginia)
New Carlisle Historic District (St. Joseph County, Indiana)
New Colonial Hotel (Somerset County, Pennsylvania)
New Hope Farm (Spartanburg County, South Carolina)
Historic farm in Spartanburg, SC
New Lyme Institute (Ashtabula County, Ohio)
New Market Presbyterian Church (Madison County, Alabama)
New Salem Baptist Church (Sevier County, Tennessee)
New Zion Historic District (Unspecified county, Kentucky)
Newberry Friends Meeting House (Orange County, Indiana)
Newport National Bank (New Castle County, Delaware)
Newton P. Carreker House (Talbot County, Georgia)
Newton Sutterfield Farmstead (Stone County, Arkansas)
Nicholas Carter House (Larue County, Kentucky)
Nicholson House (Baldwin County, Alabama)
Nicholson House and Inn (Erie County, Pennsylvania)
Nicholsonville Baptist Church (Chatham County, Georgia)
Nicking House (Johnson County, Iowa)
Nimocks House (Cumberland County, North Carolina)
Niotaze Methodist Episcopal Church (Chautauqua County, Kansas)
No. 4 Schoolhouse (Worcester County, Massachusetts)
Noftzger-Adams House (Wabash County, Indiana)
Nolte--Rooney House (Brewster County, Texas)
Norfolk City Hall (Norfolk, Virginia)
Normal Hall (Montgomery County, Indiana)
Normandy Historic District (Bedford County, Tennessee)
Norridgewock Female Academy (Somerset County, Maine)
North Bend (Charles City County, Virginia)
North Carolina Mutual Building (Richland County, South Carolina)
North Charlotte Historic District (Mecklenburg County, North Carolina)
North Fork Valley Rural Historic District (Montgomery County, Virginia)
North Milford Historic District (Kent County, Delaware)
Northampton Lumber Company Historic District (Northampton County, Virginia)
Northrup House (Allen County, Kansas)
Northumberland County Courthouse (Northumberland County, Pennsylvania)
Northwestern Hotel (Waukesha County, Wisconsin)
Built in 194, the Northwestern Hotel is better known as Club 400 with family ties to the late Les Paul
Null House (Baltimore, Maryland)
O Street Market (Washington, District of Columbia)
Oak Avenue Historic District (Jackson County, Georgia)
Oak Grove (Campbell County, Virginia)
Oak Grove School (Forsyth County, North Carolina)
Oak Hill (Fairfax County, Virginia)
Oak Hill Railroad Depot (Fayette County, West Virginia)
Oak Ridge Military Academy Historic District (Guilford County, North Carolina)
Oak Spring Farm (Rockbridge County, Virginia)
Oakdale Cotton Mill Village (Guilford County, North Carolina)
Oakland (Wood County, West Virginia)
Oakland (Sumner County, Tennessee)
Oakland City Historic District (Fulton County, Georgia)
Oaks II (Montgomery County, Maryland)
Oakton Trolley Station (Fairfax County, Virginia)
Oakwold Plantation House (Avoyelles Parish, Louisiana)
Oakwood (Howard County, Missouri)
Oatman Drug Company Building (Mohave County, Arizona)
Occoneechee Speedway (Orange County, North Carolina)
Occoquan Historic District (Prince William County, Virginia)
Octagon, The (Seneca County, Ohio)
Octagonal Poultry House (Cape May County, New Jersey)
Odd Fellows Hall (Linn County, Iowa)
Officer Farmstead (Overton County, Tennessee)
Ojo Caliente Mineral Springs (Taos County, New Mexico)
Oklahoma Odd Fellows Home at Checotah (McIntosh County, Oklahoma)
Oklahoma State Bank Building (Logan County, Oklahoma)
Old Adobe Barn (Stanislaus County, California)
Old Bethel Methodist Church (Greene County, Arkansas)
Old Borges Ranch (Contra Costa County, California)
Old Brownson School (Victoria County, Texas)
Old Courthouse (Marengo County, Alabama)
The third building to serve as the courthouse for Marengo County, Alabama.
Old Dauphin Way Historic District (Mobile County, Alabama)
Old East, University of North Carolina (Orange County, North Carolina)
Old Farm Schoolhouse (Hartford County, Connecticut)
Old Fentress County Jail (Fentress County, Tennessee)
Old Forge Farm (Frederick County, Virginia)
Old Frio County Jail (Frio County, Texas)
Old Governor's Mansion (Baldwin County, Georgia)
Old Homestead (Monroe County, Mississippi)
Old Hoopes School (Mifflin County, Pennsylvania)
Old Hotel, The (Greene County, Ohio)
Old Jail (Hancock County, Tennessee)
Old Kentucky Turnpike Historic District (Tazewell County, Virginia)
Old Main, University of Arkansas (Washington County, Arkansas)
Old Market House Museum (Goliad County, Texas)
Old Mercantile Building (Sutton County, Texas)
Old Mill of Guilford (Guilford County, North Carolina)
Old Mission House (Yukon-Koyukuk Census Area, Alaska)
Old Neck Historic District (Perquimans County, North Carolina)
Old Rectory (Bedford County, Virginia)
Old Richmond Schoolhouse and Gymnasium (Forsyth County, North Carolina)
Old Rock House (McDuffie County, Georgia)
Old Slave Mart (Charleston County, South Carolina)
Old Stagecoach Stop (Pulaski County, Missouri)
Old Stone Church (Frederick County, Virginia)
Old Town House (York County, Maine)
Old Union School (Randolph County, Arkansas)
Oldenburg Historic District (Franklin County, Indiana)
Olivenhain Town Meeting Hall (San Diego County, California)
Oliver P. Jones House (Bastrop County, Texas)
Olzie Whitehead Williams House (Wilson County, North Carolina)
Omar Chapel (Seneca County, Ohio)
Opequon Historic District (Frederick County, Virginia)
Opp Commercial Historic District (Covington County, Alabama)
Orange Springs (Orange County, Virginia)
Orange Street School (Cumberland County, North Carolina)
Oregon Creek Covered Bridge (Yuba County, California)
Covered bridge over Oregon Creek on Alleghany Road at Oregon Creek Campground
Orin Savage Cottage (Franklin County, New York)
Orme Wilson and Company Storehouse (Loudon County, Tennessee)
Oscar Hammerstein II, Farm (Bucks County, Pennsylvania)
Otto Brinkmann House (Kendall County, Texas)
Our Lady of Sorrows Chapel (La Crosse County, Wisconsin)
Owen Chapel Church of Christ (Williamson County, Tennessee)
Oxford Female Institute (Butler County, Ohio)
Ozark Courthouse Square Historic District (Christian County, Missouri)
P. A. Fry House (Bastrop County, Texas)
P. A. Smith Hotel (Grimes County, Texas)
Paducah Market House District (McCracken County, Kentucky)
Paeonian Springs Historic District (Loudoun County, Virginia)
Paisley-Rice Log House (Orange County, North Carolina)
Palo Alto Plantation (Onslow County, North Carolina)
Paoli Historic District (Madison County, Georgia)
Paris Public School (Bear Lake County, Idaho)
Paris Railroad Depot (Bourbon County, Kentucky)
Park and Bandstand (Sumter County, Alabama)
Park City Miner's Hospital (Summit County, Utah)
Park Springs Ranch Headquarters Complex (San Miguel County, New Mexico)
Parker Lumber Company Complex (Brazos County, Texas)
Parker, Charlie, Residence (New York County, New York)