Built during 1820s

"S" Bridge II (Muskingum County, Ohio)
1907 House (Jefferson Davis County, Mississippi)
A. P. Hill Boyhood Home (Culpeper County, Virginia)
Aaron Aldrich House (Cuyahoga County, Ohio)
Abbott-Page House (Erie County, Ohio)
Abner Cloud House (New Castle County, Delaware)
Abner Williams Log House (Noble County, Ohio)
Abraham Byrd House (Cape Girardeau County, Missouri)
Abraham Ditto House (Hardin County, Kentucky)
Abraham Magowan House (Fleming County, Kentucky)
Abyssinian Meeting House (Cumberland County, Maine)
Acworth Congregational Church (Sullivan County, New Hampshire)
Adams-Ryan House (Monroe County, New York)
Addison Kimball House (Lake County, Ohio)
Adsit House (Steuben County, New York)
Agler-La Follette House (Franklin County, Ohio)
Ainsley Hall House (Richland County, South Carolina)
Akron Cemetery (Independence County, Arkansas)
Albertus Ledbetter House (McDowell County, North Carolina)
Aldrich, Jacob, House (Worcester County, Massachusetts)
Alexander Ewing House (Davidson County, Tennessee)
Alexander P. and James S. Waugh House (Mercer County, Pennsylvania)
Alexander Patterson House (Meigs County, Tennessee)
Alexander Thompson House (Orange County, New York)
Alexander W. Arbuckle I, House (Greenbrier County, West Virginia)
Allegheny Aqueduct (Berks County, Pennsylvania)
Allendale Mill (Providence County, Rhode Island)
Allenwood Farm (Washington County, Vermont)
Allison, Capt. Samuel, House (Cheshire County, New Hampshire)
Almeron Durkee House (Cayuga County, New York)
Alpheus Lewis House (Clark County, Kentucky)
Ambrose Baber House (Bibb County, Georgia)
Anderson House (Botetourt County, Virginia)
Andes Historic District (Delaware County, New York)
Andrew Gregg Homestead (Centre County, Pennsylvania)
Andrew Hearn Log House and Farm (Franklin County, Kentucky)
Andrew Hoke House (Jefferson County, Kentucky)
Andrew Johnston House (Giles County, Virginia)
Andrew Scott House (Maury County, Tennessee)
Anza House (San Benito County, California)
Appleton, Nathan, Residence (Suffolk County, Massachusetts)
Applewood Farm (New London County, Connecticut)
Arcade, The (Providence County, Rhode Island)
Archibald H. Davis Plantation (Franklin County, North Carolina)
Arlington (Jefferson County, Alabama)
A former plantation house and 6 acres (24,000 m2) of landscaped gardens near downtown Birmingham, Alabama.
Arlington Plantation House (St. Landry Parish, Louisiana)
Armstrong Row (Mason County, Kentucky)
Arnold-Palmer House (Providence County, Rhode Island)
Arrowhead (Franklin County, Kentucky)
Art Gallery (Cumberland County, Maine)
Asher W. Bizzell House (Sampson County, North Carolina)
Asher's Cabin (Clarke County, Mississippi)
Ashford Academy (Windham County, Connecticut)
Ashtabula (Anderson County, South Carolina)
Historic plantation home near Pendleton, SC
Asphodel Plantation and Cemetery (East Feliciana Parish, Louisiana)
Astor Fur Warehouse (Crawford County, Wisconsin)
Athol (Caroline County, Maryland)
Atwater, George, House (New Haven County, Connecticut)
Audubon (Scott County, Kentucky)
Augusta College Historic Buildings (Bracken County, Kentucky)
Ault--Weygandt Farm (Wayne County, Ohio)
Avondale Plantation Home (East Feliciana Parish, Louisiana)
Bailey's Store (Charleston County, South Carolina)
Bainbridge Commercial Historic District (Decatur County, Georgia)
Baker's Island Light Station (Essex County, Massachusetts)
Baker, Benjamin Jr., House (Barnstable County, Massachusetts)
Balwearie (Fairfield County, South Carolina)
Early 19th century home near Winnsboro, SC
Bank Building (Accomack County, Virginia)
Bank of Louisiana (Orleans Parish, Louisiana)
Baptist New Meeting House (Merrimack County, New Hampshire)
Barber, Giles, House (Hartford County, Connecticut)
Barboursville (Orange County, Virginia)
Barcelona Lighthouse and Keeper's Cottage (Chautauqua County, New York)
Barclay Farm House (Camden County, New Jersey)
Barnes, James B., House (Middlesex County, Massachusetts)
Barrett-Chumney House (Amelia County, Virginia)
Barthel Pigeonnier (East Baton Rouge Parish, Louisiana)
Batchelder, George, House (Middlesex County, Massachusetts)
Baxter, Shubael, House (Barnstable County, Massachusetts)
Baylis, M., House (Suffolk County, New York)
Beagle Hotel (Ohio County, West Virginia)
Beall-Air (Jefferson County, West Virginia)
Beaver Dam Plantation House (Mecklenburg County, North Carolina)
Bedens Brook Bridge (Somerset County, New Jersey)
Stone arch bridge over Bedens Brook on Opossum Road
Bedford Creek Bridge (Jefferson County, New York)
Beebe Estate (Middlesex County, Massachusetts)
Beebe Windmill (Suffolk County, New York)
Beecher Hall, Illinois College (Morgan County, Illinois)
Bel Aire (Albemarle County, Virginia)
Belknap--Sulloway Mill (Belknap County, New Hampshire)
Bell Tower (Richmond, Virginia)
Belle-Hampton (Pulaski County, Virginia)
Bellevue (Burke County, North Carolina)
Bellevue (Bedford, Virginia)
Belmont Historic District (Belmont County, Ohio)
Benjamin F. Hopkins Stone Building (Portage County, Ohio)
Benjamin Gachet House (Lamar County, Georgia)
Benjamin Lundy House (Jefferson County, Ohio)
Benjamin Lundy House (Vinton County, Ohio)
Benjamin McCoy House (Kershaw County, South Carolina)
Benjamin Stephenson House (Madison County, Illinois)
Benjamin W. Davidson House (Mecklenburg County, North Carolina)
Bennett Hiatt Log House (Rockcastle County, Kentucky)
Bently Hall (Crawford County, Pennsylvania)
Berkshire Village Historic District (Tioga County, New York)
Berry Hill (Orange County, Virginia)
Bethel Church and Graveyard (Fountain County, Indiana)
Bethel Presbyterian Church (Claiborne County, Mississippi)
Bethesda Presbyterian Church (York County, South Carolina)
Historic 19th Century Presbyterian Church near McConnells, SC
Bethesda Presbyterian Church (Kershaw County, South Carolina)
Bethlehem Church (Washington County, Indiana)
Pioneer Church built in 1824
Bialystoker Synagogue (New York County, New York)
Bingham-Brewer House (Montgomery County, Maryland)
Black Homestead Farm (Greene County, Illinois)
Black House (Warren County, Tennessee)
Black Mansion (Hancock County, Maine)
Blackman-Bosworth Store (Randolph County, West Virginia)
Blackstone Canal (Providence County, Rhode Island)
Blackstone Canal (Worcester County, Massachusetts)
Blackwell Street Historic District (Morris County, New Jersey)
Blaine Hill "S" bridge (Belmont County, Ohio)
A stone arch bridge over Wheeling Creek on the National Road.
Blair House (Washington, District of Columbia)
Blair-Dunning House (Monroe County, Indiana)
Blakeley (Jefferson County, West Virginia)
Blenheim (Campbell County, Virginia)
Blink Bonnie (Fairfield County, South Carolina)
Antebellum home near Ridgeway, SC
Bloomfield (New Castle County, Delaware)
Blooming Grove Church (Orange County, New York)
Boardman, E., House (Middlesex County, Massachusetts)
Bob White Covered Bridge (Patrick County, Virginia)
Boggs Mill (Pendleton County, West Virginia)
Boscawen Academy and Much-I-Do-Hose House (Merrimack County, New Hampshire)
Boscobel Cottage (Ouachita Parish, Louisiana)
Bottle House Block (Middlesex County, Massachusetts)
Bowen-Jordan Farm (Chatham County, North Carolina)
Bower-Cox House (Ashe County, North Carolina)
Bowieville (Prince George's County, Maryland)
Bowman House (Loudon County, Tennessee)
Bowman House (Washington County, Maryland)
Bowman-Zirkle Farm (Shenandoah County, Virginia)
Boyd Tavern (Albemarle County, Virginia)
Bracebridge Hall (Edgecombe County, North Carolina)
Breckinridge Mill Complex (Botetourt County, Virginia)
Breese--Reynolds House (Rensselaer County, New York)
Brents-Lisle House (Green County, Kentucky)
Brentsville Courthouse and Jail (Prince William County, Virginia)
Brentsville Historic District (Prince William County, Virginia)
Brewer, John N.M., House (Washington County, Maine)
Brewer, Selden, House (Hartford County, Connecticut)
Brick School House (Hancock County, Maine)
Brick Tavern Stand (Schuyler County, New York)
Bridge at Falling Creek (Chesterfield County, Virginia)
Bridge Square Historic District (Monroe County, New York)
Bridgewater Woolen Mill (Windsor County, Vermont)
Bristol County Courthouse Complex (Bristol County, Massachusetts)
Bristol County Jail (Bristol County, Rhode Island)
Broad Run Bridge and Tollhouse (Loudoun County, Virginia)
Brompton (Fredericksburg, Virginia)
Brotherton Farm (Franklin County, Pennsylvania)
Brown Farmstead (Orange County, New York)
Brown House (Hamilton County, Tennessee)
Brown Marsh Presbyterian Church (Bladen County, North Carolina)
Brown Pusey House Community Center (Hardin County, Kentucky)
Brown--Moore Blacksmith Shop (Fayette County, Pennsylvania)
Brownsburg Historic District (Rockbridge County, Virginia)
Brownville Hotel (Jefferson County, New York)
Brownwood (Trumbull County, Ohio)
Bryan Lavender House (Jones County, North Carolina)
Bryan, Roderick, House (Litchfield County, Connecticut)
Bryant Hill Cemetery (Cattaraugus County, New York)
Bryn Athyn--Lower Moreland Bridge (Montgomery County, Pennsylvania)
Bucknam, Samuel, House (Washington County, Maine)
Building at 161 Spring St. (Fulton County, Georgia)
Bunker Hill (Anne Arundel County, Maryland)
Bunting Place (Accomack County, Virginia)
Burford Hill (Mercer County, Kentucky)
Burgett House And Barn (Brown County, Ohio)
Burgholtshouse (York County, Pennsylvania)
Burke's Garden Central Church And Cemetery (Tazewell County, Virginia)
Burleigh (Person County, North Carolina)
Burlington Historic District (Boone County, Kentucky)
Burnt Island Light Station (Lincoln County, Maine)
Burt-Arrington House (Nash County, North Carolina)
Butler Historic District (Butler County, Pennsylvania)
Butterfield--Sampson House (Sagadahoc County, Maine)
Byler Road (Tuscaloosa County, Alabama)
The oldest public road in Alabama still in use today.
Cabe-Pratt-Harris House (Orange County, North Carolina)
Cabins Historic District (Adair County, Missouri)
Cahas Mountain Rural Historic District (Franklin County, Virginia)
Caldwell-Hampton-Boylston House (Richland County, South Carolina)
Calhoun Mine (Lumpkin County, Georgia)
Callahan House (Pike County, Pennsylvania)
Cambridge Meetinghouse (Lamoille County, Vermont)
Campbell, David W., House (Washington County, Maine)
Canfield Casino and Congress Park (Saratoga County, New York)