Welcome to the online companion to the New Castle Historical Society's 2026 exhibition,
A Center of the American Experience for 375 Years.
Explore this page to learn more about four centuries of New Castle history.
For 375 years, the small town of New Castle has played a large part in American history.
It has helped shape the way people live in Delaware and across the entire United States.
The real heart of the New Castle story is the people who lived here—including Native Americans, Europeans, Africans, and immigrants from all over. Their lives show us the big dreams and the tough challenges that make up the American story.
In this exhibit, you’ll discover how New Castle has been at the center of the American experience for nearly four centuries.
Fur, a Fort, and Fighting:
The Birth of New Castle
Long before Europeans arrived, the land along the Delaware River belonged to Indigenous groups like the Lenni Lenape and the Susquehannock. For hundreds of years, they lived off this land, hunting in the forests and fishing in the rivers. They didn't just live here; they took great care of nature because it gave them everything they needed to survive.
In the mid-1600s, people from Sweden, the Dutch Republic (The Netherlands), and England arrived. They saw that the land was full of valuable things - especially beaver fur, which was worth a lot of money back in Europe. They all started claiming the land for themselves so they could get rich from trading.
Everyone wanted to own the Delaware River because that’s how ships moved in and out of this region. In 1651, the Dutch, led by Peter Stuyvesant, built Fort Casimir at a spot that was perfect to watch the river. A little village called New Amstel grew around the fort.
For years the Dutch, Swedes, and English fought over Fort Casimir. Finally, in 1664, the English won and took over the whole area. They changed the town's name to New Castle.
Peter Lindeström’s drawing of Fort Trefaldighet (Casimir),
circa 1655.
The Rise and Fall of Fort Casimir
In 1621, a large Dutch trading company started a colony called “New Netherland.” It was huge, covering parts of what we now call New York, New Jersey, Connecticut, and Delaware. The town of New Castle was at the very bottom edge of this colony. The problem? Sweden also claimed that same land for their own colony, “New Sweden.” Both countries wanted to own the area.
In 1651, a Dutch leader named Peter Stuyvesant built Fort Casimir along the Delaware River. He had three goals: to control every ship that sailed by, to push the Swedes out of Dutch lands, and to make sure English settlers in Maryland didn’t move further north.
Fort Casimir was small and simple. The walls were made of wood held up by piles of dirt. A large trench was dug around the outside to keep enemies away. Inside the fort were just a few basic wooden buildings for food, supplies, and about 30 or 40 soldiers.
By 1670, the fort was falling apart. Even though the fort is gone now, the spot where it used to be, near Chestnut and East Second Streets, is protected. Special scientists, called archaeologists, still dig there to learn about people of the past.
New Castle:
The Center of the Circle
After the Duke of York seized New Castle from the Dutch in 1664, King Charles II gave him all the land that makes up today’s State of Delaware as a reward.
In 1681, King Charles granted land to the north of Delaware to William Penn. Today, this land is Pennsylvania.
To protect the Duke of York’s land from Penn’s, a circle with a 12-mile radius was drawn as the boundary line between the two. The center of the circle was at the end of the Broad Dike, near the corner of Third and Chestnut Streets in New Castle. This made New Castle central to life in early Delaware. A historical marker stands at that location today.
But the Duke of York soon gave Penn the land within the circle as well as the land south all the way to Cape Henlopen. Part of the circle became the boundary between Pennsylvania and the “Three Lower Counties on Delaware.” It is still Delaware’s northern border and extends all the way to New Jersey’s riverfront.
