Seaway Trail Discovery Center

Union Hotel, also known as Barrow's Hotel, is a historic hotel located at Sackets Harbor in Jefferson County, New York. It is a 3+1⁄2-story stone building, 51 feet by 69 feet, over a full basement. The original structure was built in 1817–1818. The interior features distinctive Federal woodwork. It functioned as a hotel into the 1860s, then was used as a Masonic Lodge. In 1972 New York State acquired the building and rehabilitated it for use as the Visitor Center for the Sackets Harbor Battlefield State Historic Site. In July 2000, an addition was built and it was converted to serve as the Seaway Trail Discovery Center. It was listed on the National Register of Historic Places in 1972.

Fort Tompkins (1812–1815) was a redoubt at Sackets Harbor, New York. A minor redoubt in a fortified line of four such "forts" (Kentucky, Virginia, Chauncey, Stark) anchored at Fort Pike (later Madison Barracks) on the bay, protecting the land side of Sackets Harbor.

The Second Battle of Sacket's Harbor, or simply the Battle of Sacket's Harbor, took place on 29 May 1813, during the War of 1812. A British force was transported across Lake Ontario and attempted to capture the town, which was the principal dockyard and base for the American naval squadron on the lake. Twelve warships were built here. The British were repulsed by American regulars, militia, marines and sailors, although the attack resulted in the destruction of naval stores and self-inflicted damage to American warships.

Sackets Harbor Village Historic District is a national historic district located at Sackets Harbor in Jefferson County, New York. The district includes 143 contributing buildings, among a total of 156 buildings in the historic central core of the village. The majority of the buildings were constructed during the first century of European-American settlement, 1801 to 1900. It was listed on the National Register of Historic Places in 1983.

Sackets Harbor Central School District is an elementary and secondary school district located in Sackets Harbor, New York. It is a small, single-building preschool-12 school of approximately 475 students.

Elisha Camp House is a historic home located at Sackets Harbor in Jefferson County, New York. It was built about 1808–1815 and is a 2+1⁄2-story red brick building that is a remarkably well preserved example of an elegant Federal-style dwelling. It features flat, geometric carving; Adamesque ornament; Palladian windows; elliptical fanlights; and a quality of reserve and refinement. It was listed on the National Register of Historic Places in 1973.

Sackets Harbor (earlier spelled Sacketts Harbor) is a village in Jefferson County, New York, United States, on Lake Ontario. As of the 2020 census, Sackets Harbor had a population of 1,351. The village was named after land developer and owner Augustus Sackett, who founded it in the early 1800s. Sackets Harbor is in the western part of the town of Hounsfield and is west of Watertown. The heart of the village, with a Main Street and well-preserved 19th century buildings, has been recognized as the Sackets Harbor Village Historic District and listed on the National Register of Historic Places in 1983. To support the War of 1812, the US Navy built a major shipyard and its headquarters for the Great Lakes at the village. Within a short period, more than 3,000 men worked at the shipyard. The Army constructed earthworks, forts, barracks and supporting infrastructure to defend the village and navy shipyard, and its troops also camped in the village. The thousands of military personnel made it seem like a city. By the fall of 1814, this was the third-largest population center in the entire state, after Albany and New York City. With its strategic protected harbor on Lake Ontario and military installations, the village had national importance through the 19th century. Soon after the war, the Army strengthened its defenses on the northern frontier by constructing Madison Barracks. The village also developed a commercial shipyard and many business connections to communities around the Great Lakes. Its businessmen were also connected to bases in the major markets of Louisville, Kentucky, and New Orleans. In 1817 a consortium of local businessmen supported construction of the 240-ton Ontario, the first US steamboat on the Great Lakes. In July 1834, the commercial schooner Illinois from Sackets Harbor was the first to enter the harbor of the new settlement of Chicago. Sackets Harbor Battlefield State Historic Site commemorates a battle during the War of 1812 and the contribution of the area to the United States defense.

Sackets Harbor Battlefield State Historic Site is a historically important location in Jefferson County, New York, United States. The historic site is south of the Village of Sackets Harbor, bordering Lake Ontario in the Town of Hounsfield. Two battles were fought near this location during the War of 1812. Some 3,000 men worked at the shipyard building warships, and the village was fortified and garrisoned with thousands of troops. The site includes exhibits, a restored 1850s Navy Yard and Commandant's House, outdoor signs, and guided and self-guided tours. During the summer months, interpretive guides, in regimental style, re-enact a soldier's camp life in 1813. It was listed on the National Register of Historic Places in 1974. The battlefield designation includes the 24-acre Horse Island, the site of some British action during the Second Battle of Sacket's Harbor. In July 2017, the Civil War Trust (now the American Battlefield Trust) announced that it had acquired the island for preservation, under the first grant in the United States made for a War of 1812 site by the National Park Service's American Battlefield Land Grant program. The American Battlefield Trust and its partners have saved more than 25 acres of the battlefield as of mid-2023.

Madison Barracks was a military installation established in 1813 or 1815 at Sackets Harbor that was built for occupation by 600 U.S. troops, a few years after the War of 1812. It was named for James Madison who had just completed his presidency in 1817. Construction began under the name Fort Pike. The facility is a National Historic Landmark and a historic district located in Jefferson County, New York. The district includes 86 contributing buildings and two contributing structures. It includes the stone hospital, bakery, several warehouses known as "Stone Row," a stone water tower, and a series of brick buildings constructed in the 1890s as officers quarters, barracks, mess hall, and weapons storage and repair building. Madison Barracks was used as a Citizens' Military Training Camp between the world wars. Madison Barracks was the U.S. Army's primary post in upstate New York until Pine Camp (later renamed Fort Drum) was opened in 1908. Madison Barracks remained an active military installation through the end of World War II, to 1947. General Mark W. Clark, a senior commander during World War II, was born at Madison Barracks in 1896 while his father Charles Carr Clark was stationed there. The grounds and remaining buildings of Madison Barracks are now part of a combined residential and business development. The Madison Barracks site was listed on the National Register of Historic Places in 1974.

Shore Farm, historically known as "Shore Farm Camp," is a historic farm complex located at Hounsfield in Jefferson County, New York. The farm complex consists of the Luff/Wardwell House, a former tenant house/milk house, and a cattle barn. The house is a stone and wood-frame structure dating to about 1822 and enlarged about 1895. Also on the property are non-contributing cabins and cottages. It was listed on the National Register of Historic Places in 1989.

Horse island is a historical site recognized in many primary sourced letters and battle records. It is an egg-shaped island with an area of about 24 acres, located in Sackets Harbor on Lake Ontario in upstate New York. The island was the site of the Battle of Sacket's Harbor and has a notable lighthouse on it.

District School No. 20 is a historic one-room school building located at Hounsfield in Jefferson County, New York. It is a one-story, rectangular one room structure built about 1835 of rubble Chaumont limestone. It was last used as a school in 1938. It was listed on the National Register of Historic Places in 1989.