Fort Warren

Georges Island, Boston Harbor, Boston, Massachusetts


Street View 


This massive pentagonal fortification--its outer walls of Quincy granite are eight feet thick--was begun in 1834 to protect Boston Harbor. One of the nation's finest 19th century coastal fortifications and the chief work of military engineer Sylvanus Thayer, it is strategically located on Georges Island, midway between the northern and southern arms of the harbor. Fort Warren is the most important Civil War site in New England, as it served as a prison for Confederate leaders and officers, including vice president Alexander Stephens. Battery Jack Adams, an unusual single gun battery within the Fort, was considered to be a key part of Boston Harbor's defense system during the Spanish-American War. -- National Historic Landmark statement of significance, August 29, 1970

National Register information 

Posted to the National Register of Historic Places on August 29, 1970
Reference number
Areas of significance
Military; Architecture
Level of significance
Evaluation criteria
A - Event; C - Design/Construction
Property type
Historic function
Current functions
Museum; Park
Periods of significance
1875-1899; 1850-1874; 1825-1849
Significant years
1834; 1865
Number of properties
Contributing buildings: 2
Contributing structures: 1
Contributing sites: 1

Update Log 

  • January 28, 2017: New Street View added by Brian Bartlett