Harbor Defense Museum

{{Use dmy dates|date=February 2025}}

{{infobox museum

| name = Harbor Defense Museum

| established = {{Start date and age|1980}}

| location = Fort Hamilton, Bay Ridge, Brooklyn New York, United States

| coordinates = {{coord|40|36|29.89|N|74|1|55.41|W|region:US-NY|display=inline,title}}

| type = Military museum

| visitors = 20,000/year (1995){{Cite web |url=https://www.nydailynews.com/1995/03/05/museum-stands-its-ground/ |title=Museum Stands its Ground |accessdate=2025-02-23 |date=1995-03-05 |author=Fuentes |first=Annette |work=Daily News}}

| website = {{Official URL}}

}}

The Harbor Defense Museum, sometimes called The Caponier, located within the grounds of Fort Hamilton in the Bay Ridge section of Brooklyn is a 19th-century fort, New York City's only military museum and one of only seventy military museums in the United States that is funded and operated by the Defense Department.

Caponiers, the technical name of the structure that now houses the museum, are outworks; in the case of Fort Hamilton its mission was to protect the main fortress from rear attacks. Originally a small fort within the larger fort, it now serves as the guardian of Fort Hamilton's history.{{Cite web|url=https://query.nytimes.com/gst/fullpage.html?res=950DE1D91038F935A15756C0A96F948260|title=Out of New York's Military Past|accessdate=2008-04-30|date=1989-05-26|first=Andrew L.|last=Yarrow|work=The New York Times}} Robert E. Lee served at Fort Hamilton in the 1840s, when there was only one Army.{{Cite web|url=https://query.nytimes.com/gst/fullpage.html?res=9D0CE1DC123BF931A35755C0A967958260&sec=travel&spon=&pagewanted=all|title=What Sights to See, Big Time (and Small)|accessdate=2008-04-30|date=1991-06-02|first=Douglas|last=Martin|work=The New York Times}}

Because it was used as a warehouse after it was no longer needed for military purposes, it was better preserved than other parts of the fort. While the museum and fort were in danger of closing in the mid-1990s due to budget cuts,{{Cite web|url=https://query.nytimes.com/gst/fullpage.html?res=9406E3D71039F934A35754C0A960958260|title=Bay Ridge; A Battle to Preserve City History|accessdate=2008-04-30|date=1996-07-07|first=Sarah|last=Kershaw|work=The New York Times}} it was preserved due to an agreement between the fort and the United States Army Center of Military History and preservation efforts of the Fort Hamilton Historic Society.{{Cite web |author=Shelby |first=Joyce |date=1996-07-13 |title=Army Fort Museum Rescued |url=https://www.nydailynews.com/1996/07/31/army-fort-museum-rescued/ |accessdate=2025-02-23 |work=Daily News}} The museum continues to serve an educational role in explaining the history of the evolution of New York Harbor.{{Cite web |author=Farrell |first=Bill |date=2000-11-10 |title=Fort Hamilton Museum Salutes Military History |url=https://www.nydailynews.com/2000/11/10/fort-hamilton-museum-salutes-military-history/ |accessdate=2025-02-23 |work=Daily News}}

Fort Hamilton is the "second-oldest continuously garrisoned federal post in the nation", second only to West Point and its ties to the community are part of the charm of the museum and the fort. Although The Caponier was always prepared for battle, with a 24-pound cannon aimed at New York Harbor, the fort never experienced a battle. The museum houses an array of artifacts from New York's military history including American Revolutionary War relics, uniforms from various wars, old maps of the fort, the post's old switchboard, an exhibit on a secret tunnel that connected Fort Hamilton with another base a half-mile away, a Confederate mine and a piece of the net that protected New York Harbor from German U-boats in World War I.{{Cite web|url=https://query.nytimes.com/gst/fullpage.html?res=9D0CE5DD1630F930A35751C0A967958260|title=If You're Thinking of Living in: Fort Hamilton|accessdate=2008-04-30|date=1991-02-03|first=Jerry|last=Cheslow|work=The New York Times}} It is also the temporary home of a Bay Ridge time capsule that was unearthed prematurely due to construction.{{Cite web |first=Matthew |last=Lysiak |date=2007-11-16 |title=Time Capsule Relics Unearthed 47 Years too Early |url=https://www.nydailynews.com/2007/11/16/time-capsule-relics-unearthed-47-years-too-early/ |url-status=live |archive-url=https://web.archive.org/web/20110604220454/http://www.nydailynews.com/ny_local/brooklyn/2007/11/13/2007-11-13_time_capsule_relics_unearthed_47_years_t-1.html |archive-date=2011-06-04 |access-date=2025-02-23 |work=Daily News}}