The Twelve Mile Circle

A few months ago I came across this Wikipedia Article describing a portion of the border of Delaware and New Jersey:

Its existence dates from a deed to William Penn from the Duke of York on August 24, 1682, which granted Penn:

all that the Towne of Newcastle otherwise called Delaware and All that Tract of Land lying within the Compass or Circle of Twelve Miles about the same scituate lying and being upon the River Delaware in America And all Islands in the same River Delaware and the said River and Soyle thereof lying North of the Southermost part of the said Circle of Twelve Miles about the said Towne.

The fact that the circle extends into the Delaware River makes for a fairly unique territorial possession. Most territorial boundaries that follow watercourses split the water course between the two territories by one of two methods, either by the midpoint of the watercourse (the Grotian Method, after Hugo Grotius) or, more often, midpoint of the main flow channel, or thalweg. However, due to the text of the deed, within the Twelve-Mile Circle, all the Delaware River to the low-tide mark on the east (New Jersey) side is territory of the state of Delaware.

I’m not sure that type of water border is really that unusual though, because if I’m not mistaken, the entire portion of the Potomac River belongs to Maryland and Washington, D.C., with Virginia and later West Virginia not starting until the shore. The interesting thing here is there’s a small piece of land on the New Jersey side that actually belongs to Delaware:

That’s not a mistake. I’ve seen it on other maps too. I’ve always thought it would be great fun to have a “shoot trap with a shotgun that’s illegal in New Jersey” party on that little bit of land, plant a Delaware flag and lay claim, and just generally annoy the hell out of the anti-gun ninnies in New Jersey by taking Delaware’s “weak” gun laws over to that side of the river, and having a fun time.

Of course, this could also increase an already tense situation:

Regardless of the Supreme Court’s admonition to the two states against further litigation on this subject, they were back before the court as late as November of 2005, when New Jersey’s desire to approve plans by BP to build a liquefied natural gas terminal along the New Jersey shore of the Delaware River fell afoul of Delaware’s Coastal Zone Act. The court on January 23, 2006 appointed a special master to study the border dispute, a process likely to take years. Meanwhile the Delaware House of Representatives considered a (symbolic) bill to call out the National Guard to safeguard the State’s interests, while New Jersey legislators made comments about the Battleship New Jersey, moored upriver from the site.

Hell, I’ll join the Delaware National Guard in that case. I’m pretty sure Delaware could take New Jersey in a gunfight ;)