
Today is Delaware Day, a date steeped in historical importance. It marks the occasion when Delaware, the state where I was born and raised, became the first to ratify the U.S. Constitution in 1787. This significant act not only played a pivotal role in our nation’s founding but also led to Delaware being affectionately known as “The First State.” This historic milestone fills me with immense pride and a deep sense of connection to my Delawarean heritage. It also spurs my interest in exploring an intriguing part of the state’s history. Looking at a map of Delaware, one can’t help but wonder about the shape of its northern border. “Is it really part of a circle?” is a question that often comes to mind. The short answer is yes, but understanding its origin requires exploring the historical context behind its creation.
The story of Delaware’s border begins in the era of 17th-century European colonial expansion. The region now known as Delaware was once part of the Dutch colony New Netherland. Eager to establish their presence in the New World, the Dutch focused on trade within this region. They set up posts and settlements along the Delaware River and in other parts of the New World.

The era of Dutch expansion was destined to be brief. By 1664, with England rising as a dominant colonial power, it targeted New Netherland. An English fleet sailed into New Amsterdam, today’s New York City, and the unprepared Dutch swiftly surrendered. This power transfer placed New Netherland, including the future state of Delaware, under English rule. It specifically came under the governance of the Duke of York. This change was a crucial turning point, laying the foundation for the eventual shaping of Delaware’s borders.
In 1681, following the power shift, King Charles II granted William Penn a charter for Pennsylvania as repayment of a debt owed to Penn’s father. Penn’s vision was to establish a sanctuary for Quakers where religious freedom could flourish. However, the charter he received was somewhat ambiguous, particularly concerning the boundary of the new colony. This vagueness in the charter’s language would soon lead to complex territorial disputes.
One such dispute emerged between William Penn and Lord Baltimore of Maryland. The dispute centered on the land between the Chesapeake and Delaware Bays. This region was strategically important for its fertile land and potential as a trade route to the Atlantic. Due to ambiguities in their respective charters and a lack of clear geographical knowledge, Maryland and Pennsylvania laid overlapping claims to this area. Maryland based its claim on an earlier charter, while William Penn claimed the same land under his charter to secure trade routes for Pennsylvania. This contested region, known as the “Lower Counties on the Delaware,” fell under the jurisdiction of the Duke of York.
In 1682, the Duke settled the dispute by agreeing to lease the counties to Penn. This arrangement necessitated a well-defined boundary between Penn’s Pennsylvania and the leased land. Consequently, the Twelve-Mile Circle, centered on the courthouse in New Castle, was established to demarcate this border. This circle, with a radius of twelve miles, was designed for two purposes. It defined the northern boundary of the Lower Counties, later known as Delaware, and better defined the extent of Pennsylvania as outlined in Penn’s 1681 charter.


Selecting the New Castle courthouse as the center of the circle was significant because of its location and prominence. Initially, the center of the circle was the courthouse itself, but in 1750, it was refined to the dome of the courthouse. The establishment of the Twelve-Mile Circle, marking Delaware’s distinctive circular northern border, was a hallmark of creative problem-solving in the colonial era.

As we commemorate Delaware Day, we reflect on the rich history shaping this small yet influential state. The evolution of Delaware’s borders, from European colonial expansion to the creation of the Twelve-Mile Circle, illustrates a complex historical narrative. This history reminds us that events, decisions, and disputes have shaped places like Delaware. For those of us connected to the state through birth, heritage, or an appreciation of its history, Delaware Day is a celebration of our unique journey. Despite its modest size, Delaware’s role in our nation’s founding and the stories woven along its borders are significant. On Delaware Day, we honor “The First State’s” rich heritage, and as we look toward our future, it’s unmistakably clear that the sun is shining over our beloved Delaware.