California
Often referred to as "The Rock" or simply Alcatraz, the island has been the location of a lighthouse, a fort, a military and federal prison and an American Indian protest. It has become a popular tourist attraction.
Claymont, New Castle County, Delaware, 19703
The Block House was originally designed for defense against local Indians. It was constructed in 1654 by John Risingh, Governor of the Colony of New Sweden and is the only house remaining of original settlement on Naaman's Creek.
Saint Augustine, St. John's County, Florida
Built between 1672 and 1695, Castillo de San Marcos was the first masonry fort constructed to defend Saint Augustine. It was known as Fort St. Mark from 1763 until 1784 while under British control and Fort Marion from 1821 until 1942.
Mandan, Morton County, North Dakota
The Fort Abraham Lincoln State Park is home to an Indian Village and reconstructed military buildings including the Custer House.
Newport, Rhode Island
Fort Adams is a former United States Army post in Newport, Rhode Island, established on July 4, 1799 as a First System coastal fortification, and named for President John Adams, who was in office at the time.
Philadelphia, Pennsylvania
Originally called Fort Island Battery, Fort Mifflin was commissioned in 1771. During the American Revolutionary War, the fort was a centerpiece of the British conquest of Philadelphia.
Gasque, Baldwin County, Alabama
The post was named in honor of Revolutionary War hero Daniel Morgan. Construction was completed in 1834 and it was first garrisoned in March of that year. In 2007, it was listed as "one of the nation's 10 most endangered battle sites."
Charleston, South Carolina
The fort was named after General Thomas Sumter, a hero of the American Revolution. On April 12, 1861, at 4:30 a.m., Confederate batteries opened fire on the fort, which started the American Civil War.
Elmore County, Alabama
The fort was first established in 1717 by the French to counter the growing influence of the British colonies of Georgia and Carolina. It was named for Louis-Alexandre de Bourbon, comte de Toulouse. Fort Jackson was later built on the site.
Williston, Williams County, North Dakota, 58801
This was the most important fur trading post on the upper Missouri until 1867. Visitors included John James Audubon, George Catlin, Father Pierre DeSmet, Sitting Bull, Karl Bodmer, and Jim Bridger.