1761 Milestone (Providence County, Rhode Island)
An historically significant Colonial-era highway marker.
18th Separate Company Armory (Warren County, New York)
2000 Block Of Eye Street, NW (Washington, District of Columbia)
69th Regiment Armory (New York County, New York)
A. E. Burckhardt House (Hamilton County, Ohio)
A. J. Dean House (Flathead County, Montana)
A. R. Webber House (Lorain County, Ohio)
A. S. Rugge House (Warren County, New York)
Abbot Hall (Essex County, Massachusetts)
Abbott Memorial Library (Penobscot County, Maine)
Abell-Gleason House (Charlottesville, Virginia)
Aberdeen Historic District (Moore County, North Carolina)
Aberdeen Historic District (Brown County, South Dakota)
Abijah C. Jay House (Grant County, Indiana)
Abner L. Harris House (Sauk County, Wisconsin)
French Second Empire House with Mansard Roof Disguising a Third Story
Abraham Beydler House (Shenandoah County, Virginia)
Abraham Glen House (Schenectady County, New York)
Abram Gaar House and Farm (Wayne County, Indiana)
Abram's Delight (Winchester, Virginia)
Academy Hill Historic District (Monroe County, Pennsylvania)
Academy Historic District (Hampden County, Massachusetts)
Academy of the Sacred Heart (Wayne County, Michigan)
Acworth Silsby Library (Sullivan County, New Hampshire)
Adam Howard House (Crawford County, Ohio)
Adam J. Stoll House (Erie County, Ohio)
Adam Kurtz House (Winchester, Virginia)
Adam Sr. Schantz House (Montgomery County, Ohio)
Adams Academy (Norfolk County, Massachusetts)
Adams and Sickles Building (Mercer County, New Jersey)
Adams Building (Norfolk County, Massachusetts)
Adams County Courthouse (Adams County, Indiana)
Adams Power Plant Transformer House (Niagara County, New York)
Adams School (Hancock County, Ohio)
Adams, Dr. Daniel, House (Cheshire County, New Hampshire)
Adams, John, School (Norfolk County, Massachusetts)
Adams-Gray House (Coshocton County, Ohio)
Adams-Nervine Asylum (Suffolk County, Massachusetts)
Adams-Pickering Block (Penobscot County, Maine)
Adath Israel Cemetery (Jefferson County, Kentucky)
Addison Baptist Church (Addison County, Vermont)
Adelaide Avenue School (Ontario County, New York)
Former school divided into apartments
Administration Building (Roosevelt County, New Mexico)
Adolph Boesel House (Auglaize County, Ohio)
Advance Mills Historic District (Albemarle County, Virginia)
African Meetinghouse (Suffolk County, Massachusetts)
Ag Hill Complex (Centre County, Pennsylvania)
Ahavas Shalom Reform Temple (Noble County, Indiana)
Ahwahnee Hotel (Mariposa County, California)
Aiken Winter Colony Historic District II (Aiken County, South Carolina)
Aiken, Abraham, House (Essex County, New York)
Airview Historic District (Frederick County, Maryland)
Airville (Gloucester County, Virginia)
Airy Castle (Bourbon County, Kentucky)
Akron Rural Cemetery Buildings (Summit County, Ohio)
Historic Gothic Cemetery and Supporting Buildings
Alban Towers Apartment Building (Washington, District of Columbia)
Albert Kahn House (Wayne County, Michigan)
Albert Neukom House (Lucas County, Ohio)
Albert W. Henn Mansion (Cuyahoga County, Ohio)
Albertville (Former) U.S. Post Office (Marshall County, Alabama)
Built in 1931 under Andreew Mellon, now serving the Board of Education
Alderson Historic District (Unspecified county, West Virginia)
Aldred, John E., Estate (Nassau County, New York)
Aldrich Free Public Library (Windham County, Connecticut)
Alexander and Cornelia Lewthwaite House (Multnomah County, Oregon)
Alexander Davis House (Franklin County, Ohio)
Alexander P. and James S. Waugh House (Mercer County, Pennsylvania)
Alexandra, The (Hamilton County, Ohio)
Alexandria City Hall (Alexandria, Virginia)
Alfred Dunk House (Broome County, New York)
Alfred H. Renshaw House (Albany County, New York)
Alfred Horatio Belo House (Dallas County, Texas)
Alfred W. Henson House (White County, Arkansas)
Alice Paul Birthplace (Burlington County, New Jersey)
All Hallows Episcopal Church (Worcester County, Maryland)
All Saints Episcopal Church (Westchester County, New York)
All Saints' Chapel (Ulster County, New York)
All Saints' Church (Suffolk County, Massachusetts)
All Saints' Church (Hillsborough County, New Hampshire)
All Soul's Chapel (Androscoggin County, Maine)
All Souls Congregational Church (Penobscot County, Maine)
Allegheny Furnace (Blair County, Pennsylvania)
Allen County Courthouse (Allen County, Ohio)
Allen House (Middlesex County, Massachusetts)
Allen School (Bureau County, Illinois)
Allen, Charles, House (Worcester County, Massachusetts)
Allen, James House (Fayette County, Kentucky)
Allenhurst Railroad Station (Monmouth County, New Jersey)
Allentown Historic District (Erie County, New York)
Allentown Historic District (Monmouth County, New Jersey)
Allgates (Delaware County, Pennsylvania)
Allie Corn House (Boone County, Kentucky)
Allston Congregational Church (Suffolk County, Massachusetts)
Almon G. McCorkle House (Trumbull County, Ohio)
Alms and Doepke Dry Goods Company (Hamilton County, Ohio)
Almshouse (Middlesex County, Massachusetts)
Alpha Delta Phi Fraternity House (Champaign County, Illinois)
Alpha Delta Pi Sorority House (Champaign County, Illinois)
Alpha Xi Delta Sorority Chapter House (Champaign County, Illinois)
Alpheus Gay House (Hillsborough County, New Hampshire)
Altona (Jefferson County, West Virginia)
Alvah Stone Mill (Franklin County, Massachusetts)
Amawalk Friends Meeting House (Westchester County, New York)
Ambler Heights Historic District (Cuyahoga County, Ohio)
Ambrose Hall (Scott County, Iowa)
Amelia S. Givin Free Library (Cumberland County, Pennsylvania)
American Antiquarian Society (Worcester County, Massachusetts)
American Club (Sheboygan County, Wisconsin)
The only AAA Five Diamond Resort Hotel in the Midwest
Ames Cottage (Franklin County, New York)
Ames Hill/Crescent Hill District (Hampden County, Massachusetts)
Ames Manufacturing Company (Hampden County, Massachusetts)
Amherst Central Business District (Hampshire County, Massachusetts)
Amherst West Cemetery (Hampshire County, Massachusetts)
Amon Clarence Thomas House (Posey County, Indiana)
Amos Lawrence House (Bennington County, Vermont)
Anchorage, The (Essex County, New Jersey)
Andalusia (Bucks County, Pennsylvania)
Anderson House (York County, South Carolina)
Anderson House (New Castle County, Delaware)
Anderson-Shaffer House (Butler County, Ohio)
Andover Street Historic District (Middlesex County, Massachusetts)
Andrew Dickson White House (Tompkins County, New York)
Andrew Ferguson House (Coshocton County, Ohio)
Andrew Snable House (Sussex County, New Jersey)
Andrew Ten Eyck House (Somerset County, New Jersey)
Andrews Methodist Church (Taylor County, West Virginia)
Andrews United Methodist Church (New York County, New York)
Angelo Marre House (Pulaski County, Arkansas)
Angier, John B., House (Middlesex County, Massachusetts)
Angle Farm (Franklin County, Pennsylvania)
Angle Tree Stone (Unspecified county, Massachusetts)
Ann E. Lewis Bernhard House (Jefferson County, Ohio)
Ann Street Historic District (Hartford County, Connecticut)
Anna Town Hall (Shelby County, Ohio)
Annapolis National Cemetery (Anne Arundel County, Maryland)
Annville Historic District (Lebanon County, Pennsylvania)
Ansel Clark House (Lorain County, Ohio)
Anthony Pitzer Jr., House (Licking County, Ohio)
Anthony--Corwin Farm (Morris County, New Jersey)
Antietam Hall (Washington County, Maryland)
Applewood (Genesee County, Michigan)
Appomattox Iron Works (Petersburg, Virginia)
Aquia Church (Stafford County, Virginia)
Arcadia (Frederick County, Maryland)
Arch and Ridge Streets Historic District (Marquette County, Michigan)
Argent Apartments (Warren County, New York)
Arlington (Madison County, Kentucky)
Arlington Apartments (Waukesha County, Wisconsin)
The only Tudor Revival apartment building in Waukesha
Arlington Heights Historic District (Arlington County, Virginia)
Arlington Village Historic District (Arlington County, Virginia)
Arlington Village Historic District (Bennington County, Vermont)
Armitage (Terrebonne Parish, Louisiana)
Armory of the First Corps of Cadets (Suffolk County, Massachusetts)
Armour-Stiner House (Westchester County, New York)
Army Theatre (Dawes County, Nebraska)
Arnett-Fullen House (Boulder County, Colorado)
Arnheim (Radford, Virginia)
Arthur J. Dunham House (Cook County, Illinois)
Arthur P. Stitzel House (Jefferson County, Kentucky)
Arthur Perkins House (Rutland County, Vermont)
Arts and Industries Building (Washington, District of Columbia)
Arts Club of Washington (Washington, District of Columbia)
Asa Stower House (Warren County, New York)
Asa Walton House (Chester County, Pennsylvania)
Asahel Kidder House (Rutland County, Vermont)
Asbury United Methodist Church (Cheshire County, New Hampshire)
Ash Hill (Prince George's County, Maryland)
Ash Street School (Hillsborough County, New Hampshire)
Ashburnham Center Historic District (Worcester County, Massachusetts)
Ashcroft (Ontario County, New York)
Ashland Masonic Lodge Building (Jackson County, Oregon)
Ashworth and Jones Factory (Worcester County, Massachusetts)
Assington (Middlesex County, Massachusetts)
Association Residence Nursing Home (New York County, New York)
Astor Home for Children (Dutchess County, New York)
Asylum Avenue District (Hartford County, Connecticut)
Atchison Post Office (Atchison County, Kansas)
Athens State Hospital Cow Barn (Athens County, Ohio)
Atlantic Coast Line Railroad Station (Cumberland County, North Carolina)
Attleborough Falls Gasholder Building (Bristol County, Massachusetts)
Audiffred Building (San Francisco County, California)
Auditor's Building Complex (Washington, District of Columbia)
Auditorium Dance Hall, The (Pierce County, Washington)
August Meyer House (Jackson County, Missouri)
August Sauer House (Campbell County, Kentucky)
Augusta Apartment Building (Washington, District of Columbia)
Augusta City Hall, Former (Kennebec County, Maine)
Augusta Historic District (Bracken County, Kentucky)
Augusta Military Academy (Augusta County, Virginia)
Augustine Paper Mill (New Castle County, Delaware)
Ault--Weygandt Farm (Wayne County, Ohio)
Aurora Highlands Historic District (Arlington County, Virginia)