18th Century

"The Rim" and Site of Fort Foster (Washington County, Maine)
1724 Chester Courthouse (Delaware County, Pennsylvania)
1761 Milestone (Providence County, Rhode Island)
An historically significant Colonial-era highway marker.
1767 Milestones (Unspecified county, Massachusetts)
1790 Footprints (Hawaii County, Hawaii)
1790 House (Middlesex County, Massachusetts)
A. T. House (Greene County, New York)
Aaron Atherton House (Larue County, Kentucky)
Aaronsburg Historic District (Centre County, Pennsylvania)
Abbeville (Lancaster County, Pennsylvania)
Abbeville Historic District (Abbeville County, South Carolina)
Historic business and residential district in Abbeville, SC
Abbott-Decou House (Mercer County, New Jersey)
Abel and Mary Nicholson House (Salem County, New Jersey)
Abingdon Church (Gloucester County, Virginia)
Abingdon Glebe House (Gloucester County, Virginia)
Abingdon Historic District (Washington County, Virginia)
Abington Congregational Church (Windham County, Connecticut)
Abner Gaines House (Boone County, Kentucky)
Abner Gaines House - built in 1790, and first stage stop between Cincinnati, OH and Lexington, KY.
Abraham Barton House (Fayette County, Kentucky)
Abraham Glen House (Schenectady County, New York)
Abraham Hite House (Jefferson County, Kentucky)
Abraham Yates House (Schenectady County, New York)
One and a half story wood frame and brick house built in 1730
Abram Ackerman House (Bergen County, New Jersey)
Abram Demaree House (Bergen County, New Jersey)
Abram's Delight (Winchester, Virginia)
Abrams Plains (Granville County, North Carolina)
Absalom Scales House (Rutherford County, Tennessee)
Academy Hill Historic District (Essex County, Massachusetts)
Acadian House (St. Martin Parish, Louisiana)
Acadian Landing Site (Aroostook County, Maine)
Achenbach House (Bergen County, New Jersey)
Ackerman--Smith House (Bergen County, New Jersey)
Ackerman-Boyd House (Bergen County, New Jersey)
Ackerman-Dater House (Bergen County, New Jersey)
Ackerman-Demarest House (Bergen County, New Jersey)
Ackerman-Zabriskie-Steuben House (Bergen County, New Jersey)
Adam Kurtz House (Winchester, Virginia)
Adam Monin House (Hardin County, Kentucky)
Adam Stephen House (Berkeley County, West Virginia)
Adam Vandelinda House (Bergen County, New Jersey)
Adams Farm (Cheshire County, New Hampshire)
Adams Homestead Farm (Sagadahoc County, Maine)
Adams National Historic Site (Norfolk County, Massachusetts)
Adams, Abraham, House (Essex County, Massachusetts)
Adams, Benjamin, House (Worcester County, Massachusetts)
Adams, Dr. Daniel, House (Cheshire County, New Hampshire)
Adams, John, Homestead--Wellscroft (Cheshire County, New Hampshire)
Adams--Clarke House (Essex County, Massachusetts)
Adams-Magoun House (Middlesex County, Massachusetts)
Adsit Log House (Essex County, New York)
African Burying Ground (New York County, New York)
African--American Cemetery, The (Orange County, New York)
Airlie (Adams County, Mississippi)
Airy Mount (Woodford County, Kentucky)
Alamance Battleground State Historic Site (Alamance County, North Carolina)
Alan W. Corson Homestead (Montgomery County, Pennsylvania)
Albert Smith House (Bergen County, New Jersey)
Albertus Van Loon House (Greene County, New York)
Alderson Historic District (Unspecified county, West Virginia)
Aldrich, Peter, Homestead (Ulster County, New York)
Alexander and James Linn Homestead (Somerset County, New Jersey)
Alexander Bishop House (Knox County, Tennessee)
Alexander Long House (Rowan County, North Carolina)
Alexander McMillan House (Knox County, Tennessee)
Alexander-Cleveland House (Elbert County, Georgia)
Alexander-Withrow House (Lexington, Virginia)
Alexandre Latiolais House (Lafayette Parish, Louisiana)
Alexandria Historic District (Alexandria, Virginia)
Alfred Shaker Historic District (York County, Maine)
All Faith Church (St. Mary's County, Maryland)
All Hallows Episcopal Church (Worcester County, Maryland)
All Hallows' Church (Anne Arundel County, Maryland)
All Saints' Church (Calvert County, Maryland)
Allaire Village (Monmouth County, New Jersey)
Allee House (Kent County, Delaware)
Allen House (Alamance County, North Carolina)
Allen's Cider Mill (Hartford County, Connecticut)
Allen, Elisha, House (Bristol County, Massachusetts)
Allen, Stephen, House (Kent County, Rhode Island)
Allen, Zachariah, House (Providence County, Rhode Island)
Allgates (Delaware County, Pennsylvania)
Alliance Furnace (Fayette County, Pennsylvania)
Allis-Bushnell House (New Haven County, Connecticut)
Allmand-Archer House (Norfolk, Virginia)
Alloways Creek Friends Meetinghouse (Salem County, New Jersey)
Allstadt House and Ordinary (Jefferson County, West Virginia)
Allyn, Capt. Benjamin, II, House (Hartford County, Connecticut)
Almshouse Farm at Machipongo (Northampton County, Virginia)
Alna Meetinghouse (Lincoln County, Maine)
Alna School (Lincoln County, Maine)
Alston House (Moore County, North Carolina)
Altona (Jefferson County, West Virginia)
Amelia Cottage Museum (Suffolk County, New York)
Amelung House and Glassworks (Frederick County, Maryland)
American Philosophical Society Hall (Philadelphia County, Pennsylvania)
Amherst West Cemetery (Hampshire County, Massachusetts)
Amis House (Hawkins County, Tennessee)
Amos Baldwin House (Litchfield County, Connecticut)
Amos Evans House (Burlington County, New Jersey)
Amos Palmer House (Bucks County, Pennsylvania)
Amoureux House (Ste. Genevieve County, Missouri)
Anchorage, The (Northumberland County, Virginia)
Anderson-Capner House (Mercer County, New Jersey)
Andre, Maj. John, Monument (Rockland County, New York)
Andrew Baker House (St. Francois County, Missouri)
Andrew Ellicott House (Lancaster County, Pennsylvania)
Andrew Fisher House (New Castle County, Delaware)
Andrew Mann Inn (Otsego County, New York)
Andrew Rabb House (Fayette County, Pennsylvania)
Andrew, William, House (New Haven County, Connecticut)
Andrews, Luman, House (Hartford County, Connecticut)
Andrews, Moses, House (New Haven County, Connecticut)
Andrews--Luther Farm (Providence County, Rhode Island)
Andrews-Moore House (Franklin County, North Carolina)
Andries Thomas Van Buskirk House (Bergen County, New Jersey)
Angel Island, U.S. Immigration Station (Marin County, California)
Angle Tree Stone (Unspecified county, Massachusetts)
Angustias Shipwreck Site (Monroe County, Florida)
Anne Arundel County Free School (Anne Arundel County, Maryland)
Annefield (Clarke County, Virginia)
Annville Historic District (Lebanon County, Pennsylvania)
Anthony Morris House (Montgomery County, Pennsylvania)
Apple Tavern (Albany County, New York)
Appler--Englar House (Carroll County, Maryland)
Appleton Farm (Cheshire County, New Hampshire)
Appleton--Hannaford House (Cheshire County, New Hampshire)
Appomattox Manor (Hopewell, Virginia)
Apponegansett Meeting House (Bristol County, Massachusetts)
Appoquinimink Friends Meetinghouse (New Castle County, Delaware)
Aquia Church (Stafford County, Virginia)
Ar-Qua Springs (Berkeley County, West Virginia)
Arbuckle Place (Accomack County, Virginia)
Arcadia (Frederick County, Maryland)
Arcadia Plantation (Georgetown County, South Carolina)
Archibald Henderson Law Office (Rowan County, North Carolina)
Archibald--Adams House (Washington County, Maine)
Archibald-Vroom House (Bergen County, New Jersey)
Ariaanje Coeymans House (Albany County, New York)
Arlington (Somerset County, Maryland)
Arneytown Historic District (Burlington County, New Jersey)
Arnold Potter House (Yates County, New York)
Operating farm w/ Private Residence
Arnold S. Naudain House (New Castle County, Delaware)
Arnold Trail to Quebec (Unspecified county, Maine)
Arnold Trail to Quebec (Kennebec County, Maine)
Arnold, Israel, House (Providence County, Rhode Island)
Arnold, John, House (Providence County, Rhode Island)
Arnoldus Vander Horst House (Charleston County, South Carolina)
Artisan's House (Anne Arundel County, Maryland)
Ascutney Mill Dam Historic District (Windsor County, Vermont)
Ash Lawn-Highland (Albemarle County, Virginia)
Ashlawn (New London County, Connecticut)
Ashton Historic District (New Castle County, Delaware)
Aspen Lawn (Southampton County, Virginia)
Aspendale (Kent County, Delaware)
Aspenvale Cemetery (Smyth County, Virginia)
Atsion Village (Burlington County, New Jersey)
Attmore-Oliver House (Craven County, North Carolina)
Augusta Downtown Historic District (Richmond County, Georgia)
Augusta Stone Church (Augusta County, Virginia)
Augustus Lutheran Church (Montgomery County, Pennsylvania)
Avero House (St. Johns County, Florida)
Avery House (New London County, Connecticut)
Avondale (Carroll County, Maryland)
Ayers-Allen House (Middlesex County, New Jersey)
Babcock--Smith House (Washington County, Rhode Island)
Babson-Alling House (Essex County, Massachusetts)
Bachelor's Hope (Queen Anne's County, Maryland)
Back River Farm (Strafford County, New Hampshire)
Backus, Nathaniel, House (New London County, Connecticut)
Bacon, Jabez, House (Litchfield County, Connecticut)
Bacon--Morse Historic District (Worcester County, Massachusetts)
Bacon-Gleason-Blodgett Homestead (Middlesex County, Massachusetts)
Badger, Rev. Stephen, House (Middlesex County, Massachusetts)
Baily Farm (Chester County, Pennsylvania)
Baker Farm (Washington County, Maryland)
Baker, Judah, Windmill (Barnstable County, Massachusetts)
One of Cape Cod's restored windmills
Baker, Nathaniel, House (Barnstable County, Massachusetts)
Baker, Sebastian, Stone House (Ulster County, New York)
Baker-Brearley House (Mercer County, New Jersey)
Baldwin, Caleb, Tavern (Fairfield County, Connecticut)
Baldwin, Loammi, Mansion (Middlesex County, Massachusetts)
Baldwin, Zaccheus, House (New Haven County, Connecticut)
Baldwin-Grantham House (Berkeley County, West Virginia)
Baldwinville Village Historic District (Worcester County, Massachusetts)
Ball-Sellers House (Arlington County, Virginia)
Ballard Farm (Franklin County, Vermont)
Ballard-Maupin House (Albemarle County, Virginia)
Ballou House (Providence County, Rhode Island)
Ballou--Weatherhead House (Providence County, Rhode Island)
Balthis House (Warren County, Virginia)
Bancroft, Samuel, House (Middlesex County, Massachusetts)
Bancroft, Timothy, House (Cheshire County, New Hampshire)