Fort Jefferson
E55124
19th-century fortification
United States National Monument component
brick masonry structure
coastal fortress
historic site
Fort Jefferson is a massive 19th-century coastal fortress located on Garden Key in the remote Dry Tortugas of Florida, known as one of the largest brick masonry structures in the Western Hemisphere.
All labels observed (7)
| Label | Occurrences |
|---|---|
| Fort Jefferson canonical | 11 |
| Fort Jefferson, Dry Tortugas, Florida | 5 |
| Fort Jefferson National Monument | 2 |
| Fort Jefferson (on Garden Key) | 1 |
| Fort Jefferson State Memorial | 1 |
| Fort Jefferson on Garden Key | 1 |
| Fort Jefferson prison | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T439615 — resolving that mention is where its identity was fixed. The disambiguator weighed these candidate entities and picked the highlighted one (or “None”, minting a new entity). This is how homonymy is resolved: the same surface form can point to different entities.
NED1
Entity disambiguation (via context triple)
gpt-5-mini-2025-08-07
Target entity: Fort Jefferson Context triple: [Dry Tortugas National Park, hasPart, Fort Jefferson]
-
A.
Fort Pickens
Fort Pickens is a historic 19th-century coastal defense fort on the western end of Santa Rosa Island that played a key role in the defense of Pensacola Bay and remained in Union hands throughout the American Civil War.
-
B.
Fort Sumter
Fort Sumter is a coastal fortification in Charleston Harbor, South Carolina, best known as the site where the first shots of the American Civil War were fired in April 1861.
-
C.
Key West Lighthouse
Key West Lighthouse is a historic 19th-century lighthouse and museum in Key West, Florida, known for its panoramic island views and maritime heritage exhibits.
-
D.
La Fortaleza
La Fortaleza is the historic governor’s mansion and fortress in Old San Juan, Puerto Rico, recognized as one of the oldest continuously used executive residences in the Americas and a UNESCO World Heritage Site.
-
E.
High Rock Tower
High Rock Tower is a historic stone observation tower and former lighthouse in Lynn, Massachusetts, known for its panoramic coastal views and public park setting.
- F. None of above. chosen
- G. Unsure - the case is ambiguous/there is not enough information to decide.
NED2
Entity disambiguation (via description)
gpt-5-mini-2025-08-07
Target entity: Fort Jefferson Target entity description: Fort Jefferson is a massive 19th-century coastal fortress located on Garden Key in the remote Dry Tortugas of Florida, known as one of the largest brick masonry structures in the Western Hemisphere.
-
A.
Fort Pickens
Fort Pickens is a historic 19th-century coastal defense fort on the western end of Santa Rosa Island that played a key role in the defense of Pensacola Bay and remained in Union hands throughout the American Civil War.
-
B.
Fort Sumter
Fort Sumter is a coastal fortification in Charleston Harbor, South Carolina, best known as the site where the first shots of the American Civil War were fired in April 1861.
-
C.
Key West Lighthouse
Key West Lighthouse is a historic 19th-century lighthouse and museum in Key West, Florida, known for its panoramic island views and maritime heritage exhibits.
-
D.
La Fortaleza
La Fortaleza is the historic governor’s mansion and fortress in Old San Juan, Puerto Rico, recognized as one of the oldest continuously used executive residences in the Americas and a UNESCO World Heritage Site.
-
E.
High Rock Tower
High Rock Tower is a historic stone observation tower and former lighthouse in Lynn, Massachusetts, known for its panoramic coastal views and public park setting.
- F. None of above. chosen
Statements (50)
| Predicate | Object |
|---|---|
| instanceOf |
19th-century fortification
ⓘ
United States National Monument component ⓘ brick masonry structure ⓘ coastal fortress ⓘ historic site ⓘ |
| accessibleBy |
boat
ⓘ
seaplane ⓘ |
| administeredBy | National Park Service ⓘ |
| approximateNumberOfBricks | over 16 million ⓘ |
| area | approximately 16 acres ⓘ |
| constructionMaterial |
brick
ⓘ
masonry ⓘ |
| country |
United States
ⓘ
linked to:
United States of America
|
| distanceFromKeyWest | about 70 miles west of Key West ⓘ |
| endDate | circa 1875 ⓘ |
| feature |
bastions
ⓘ
casemates ⓘ lighthouse ⓘ moat ⓘ parade ground ⓘ sally port ⓘ three-tiered gun emplacements ⓘ |
| garrisonedBy |
Union Army
ⓘ
United States Army ⓘ |
| heritageDesignation |
National Historic Landmark
ⓘ
listed on the National Register of Historic Places ⓘ |
| heritageDesignationDate | 1970 ⓘ |
| locatedIn |
Dry Tortugas
ⓘ
linked to:
Dry Tortugas National Park
Florida ⓘ Garden Key ⓘ Monroe County, Florida ⓘ United States ⓘ
linked to:
United States of America
|
| locatedInBodyOfWater |
Gulf of Mexico
ⓘ
Straits of Florida ⓘ |
| namedAfter |
3rd President of the United States
ⓘ
Thomas Jefferson ⓘ |
| notablePrisoner |
Dr. Samuel Mudd
ⓘ
Samuel A. Mudd ⓘ
linked to:
Dr. Samuel Mudd
Samuel Mudd ⓘ
linked to:
Dr. Samuel Mudd
conspirators in the assassination of Abraham Lincoln ⓘ |
| openToPublic | true ⓘ |
| partOf | Dry Tortugas National Park ⓘ |
| region | Florida Keys ⓘ |
| shape | hexagonal ⓘ |
| startDate | 1846 ⓘ |
| superlative | one of the largest brick masonry structures in the Western Hemisphere ⓘ |
| use |
coastal defense
ⓘ
lighthouse support facility ⓘ military prison ⓘ |
| usedDuringConflict | American Civil War ⓘ |
How these facts were elicited
The pipeline generated the facts above by prompting gpt-5.1 with this entity's name + description and the instruction below.
Instruction
You are a knowledge base construction expert. Given a subject entity and a description of it, return factual statements that you know for the subject as a JSON list of dictionaries(triples), where keys must be "subject", "predicate" and "object". The number of facts may be very high, between 25 to 50 or more, for very popular subjects. For less popular subjects, the number of facts can be very low, like 5 or 10. # Requirements - If you don't know the subject at all, return an empty list. - If the subject is not a named entity, return an empty list. - Include at least one triple where predicate is "instanceOf". - Do not get too wordy. - Separate several objects into multiple triples with one object.
Input
Subject: Fort Jefferson Description of subject: Fort Jefferson is a massive 19th-century coastal fortress located on Garden Key in the remote Dry Tortugas of Florida, known as one of the largest brick masonry structures in the Western Hemisphere.
Referenced by (22)
Full triples — surface form annotated when it differs from this entity's canonical label.
linked to: Fort Jefferson
linked to: Fort Jefferson
linked to: Fort Jefferson
linked to: Fort Jefferson
linked to: Fort Jefferson
linked to: Fort Jefferson
subject linked to:
Dr. Samuel Mudd
linked to: Fort Jefferson
linked to: Fort Jefferson
subject linked to:
Edman Spangler – stagehand who assisted Booth at Ford’s Theatre
linked to: Fort Jefferson
linked to: Fort Jefferson
linked to: Fort Jefferson