Maine - Criteria: C (architecture/engineering)
| Abbe, Robert, Museum of Stone Antiquities |
| Abbott Memorial Library |
| Abyssinian Meeting House |
| Academy Building |
| Acadian Historic Buildings |
| Adams, D. V., Co.-Bussell and Weston |
| Adams-Pickering Block |
| Alden, Ebenezer, House |
| Alfred Historic District |
| Alfred Shaker Historic District |
| All Soul's Chapel |
| All Souls Congregational Church |
| Alls Souls Church |
| Alna Meetinghouse |
| Alna School |
| Amazeen House |
| AMERICAN EAGLE (schooner) |
| American Woolen Company Foxcroft Mill |
| Andover Hook and Ladder Company Building |
| Andover Public Library |
| Andrews, Lt. Robert, House |
| Androscoggin County Courthouse and Jail |
| Androscoggin Mill Block |
| Androscoggin Swinging Bridge |
| Androscoggin Yacht Club |
| Archeological Site No. 29-64 |
| Archibald-Adams House |
| Aroostook County Courthouse and Jail |
| Art Gallery |
| Atkinson Building |
| Auburn Commercial Historic District |
| Auburn Public Library |
| Augusta City Hall, Former |
| Auld-McCobb House |
| Austin-Hennessey Homestead |
| Ayer, Caleb R., House |
| Badger, Samuel, Monument |
| BAGHEERA (schooner) |
| Bagley-Bliss House |
| Bailey Farm Windmill |
| Bailey Island Cobwork Bridge |
| Bailey Island Library Hall |
| Bailey, Moses, House |
| Baker Island Light Station |
| Bangor Children's Home |
| Bangor Fire Engine House No. 6 |
| Bangor Hose House No. 5 |
| Bangor House |
| Bangor Mental Health Institute |
| Bangor Standpipe |
| Bangor Theological Seminary Historic District |
| Bangs, Algernon, House |
| Bank Block |
| Barker Mill |
| Barncastle |
| Barn on Lot 8, Range G |
| Barrell Homestead |
| Barrows-Steadman Homestead |
| Bass Harbor Head Light Station |
| Bass Harbor Memorial Library |
| Bates, Asa, Memorial Chapel |
| Bates Mill Historic District |
| Bath Historic District |
| Battery Steele |
| Battleship Maine Monument |
| Baxter House |
| Baxter Summer Home |
| Bayside Historic District |
| Bear Island Light Station |
| Beckett's Castle |
| Beechnut Hut Historic District |
| Belfast Commercial Historic District |
| Belfast Historic District |
| Belfast National Bank |
| Bell Hill Meetinghouse |
| Bennett Bridge |
| Bennett, Nathaniel and Elizabeth, House |
| Berwick Academy |
| Berwick High School |
| Beth Eden Chapel |
| Biddeford City Hall |
| Biddeford Main Street Historic District |
| Biddeford-Saco Mills Historic District |
| Bigelow-Page House |
| Bingham Free Meetinghouse |
| Black Mansion |
| Blackwoods Campground |
| Blake House |
| Blanchard, Capt. S. C., House |
| Blanchard, Ora, House |
| Blazo-Leavitt House |
| Bloomfield Academy |
| Blossom House |
| Blue Hill Historic District |
| Boarding House and Storehouse at Churchill Depot |
| Bodwell Water Power Company Plant |
| Bond Street Historic District |
| Boody, Henry, House |
| Boon Island Light Station |
| Boothbay Harbor Memorial Library |
Data from United States Park Service and Wikidata