Old Fort Niagara features one of the nation's finest collections of original 18th- and 19th-century military architecture and related artifacts. Museum collections span the years from pre-contact through 1963, from the time Native Americans used the site for hunting and fishing, through the French and British occupations of the site, until the US Army departed Fort Niagara at the height of the Cold War.
Collections include a comprehensive array of structures, artifacts and documentary materials depicting people and events throughout the site's history. The architectural collection includes six 18th-century buildings, the oldest extant structures of any type in the entire Great Lakes region. The earliest, known as the French Castle, was built in 1726 and is the oldest building in North America situated between the Appalachian Mountains and the Mississippi River. Other 18th-century buildings include an above-ground Powder Magazine (1757), Bakehouse (1762), Provisions Storehouse (1762) and two stone redoubts (1770 and 1771). Five other buildings relate to the 19th- and 20th century military post. The Fort also has three extensive areas of 18th- and 19th-century fortifications, which provide examples of changing defensive technologies spanning a century of intense military activity in North America. These include earthen and log outer walls and artillery emplacements representative of the 18th century and brick underground casemate galleries and outer wall facings dating from the 1863-72 period.
The archaeological collection (101,000 specimens) is composed entirely of objects excavated at Fort Niagara or related sites, and includes a small quantity of pre-historic material, large numbers of historic artifacts from the 1679-2000 use of the site and floral and faunal material. Because building locations throughout the history of the site are well documented and because the site's subsurface has been relatively undisturbed, artifacts can be identified in both temporal and physical contexts. For example, archaeologists excavating 1768 British officers' and enlisted men's guardhouses can compare artifacts recovered and illustrate social differences between two very different classes of people.
The general collection (1,830 artifacts) also spans the history of the site. These objects have been acquired by the Old Fort Niagara Association since 1931. While most are military in nature, special effort has been directed toward collecting objects representing the broader social and commercial impact of the site, its important role in the European/Native American relations and garrison/community interaction in the 19th and 20th centuries. This collection includes 73 pieces of artillery, 95 small arms and edged weapons, 155 pieces of military clothing, 61 pieces of equipment or accoutrements, furniture (75 pieces, most 1930s reproductions and historically significant in their own right) military insignia and ephemera relating to the garrison and to the Old Fort Niagara Association.
A significant addition to the object collection was made in 1994 with the purchase in Scotland of a US garrison flag captured when the British stormed Fort Niagara in December 1813. The huge flag (24'x28') is not only specific to the site, but has national significance as one of only about 20 extant US flags dating before 1815.
The library and archival collection is made up of 7,800 photographic images of Fort Niagara, 2,650 books and periodicals, 3,500 manuscript items and a great quantity of reproduced primary source material gathered from other institutions.