Simple question: part of Maryland, in the western half, is pretty narrow. Exactly how narrow does it get?
It’s debatable. 
On Google Maps, it looks like about two miles near Cumberland.
Assuming you mean the portion near Cumberland, it is just under 5 miles.
I flagged a mod to move this thread to GQ for you.
The area near Hancock is under 2 miles.
D’oh! Meant for GQ.
So long as this is in GD, I’m going to dispute that Maryland is narrow in any way, shape, or form. I accuse the OP of the most disgusting form of antimarylandism.
When I went to law school in Baltimore I recall Maryland was very proud of being “America in miniature,” i.e., forming a roughly representative sample of the whole country in its range of ethnicities, income levels, and occupations and industries and ways of life.
Maryland narrow indeed! The very idea! Montana is narrow!
Using a site where you can pluck lats and longs, the constriction near Hancock is smaller that that near Cumberland.
At Hancock, the longitude is 78.1802 W +/- and the latitude at the W Va border is about 39.6969 N while at the Penn border it is about 39.7226 N. From this site I get about 1.78 miles.
Related question: How, exactly, did the borders get drawn that way? I can’t see any natural boundaries in the area that would lead people to make Maryland such a weird shape, at least around Cumberland. Did they follow private property boundaries?
The northern boundary is the Mason-Dixon line, and the southern one is the Potomac River.
And as I understand it the boundary follows the southern bank of the Potomac, making the panhandle a little wider than it would be if it went down the centre of the river. (Similarly, the state boundaries along the Ohio River are along the southern bank of that river).
It’s quite cool how clearly the state line stands out on the satellite view. (Scroll westwards from here too.)
Round about here, though, the “line on the ground” seems to bulge north a little although the line on the map is straight. That driveway appears to cross into Pennsylvania.
If that is true than my calculations are incorrect, I plotted the center of the Potomac, making my result somewhat less than the true value.
Bear in mind that when colonies were established by the English, no one had properly mapped the interior of the North American east coast. The boundaries of colonies were basically set as between either random lines of latitude or the beds of rivers, with very little idea of what lay in the interior, and with very vague (or no) western boundaries. Maryland is absurdly narrow because its northern border was an arbitrary line of latitude and its southern border was a river bed that, at its mouth, was pretty far south of the Mason-Dixon line. It is very likely that no European knew at the time of establishment that, upstream, the Potomac would come within two miles of the Mason-Dixon line.
Another result of such arbitrary line-drawing is the fact that Virginia owns the very bottom of the Delmarva peninsula, even though it is completely cut off from mainland Virginia and has little natural relation to the rest of the state.
Sua
Thanks. That makes sense.
Moved from GD to GQ.
Just out of curiosity, there’s another land constriction, in Cecil County, dividing the Eastern Shore from the rest of the state.
True indeed, and it was the basis for a fascinating bit of legal lore. The state of Maryland, based on it’s ownership of the whole river to the Virginia shoreline (as the Maryland charter from 1632 established), sought to regulate Virginia and its citizens in their efforts to place pipes in the river and withdraw water for their own use. Virginia, citing a 1785 compact between the two states, said that Maryland couldn’t regulate squat: Virginia was free to take whatever water it wished.
Maryland response was: we’re sovereign, and that means we’re not bound by an agreement we made in 1785, even if that agreement says what you claim. Which it doesn’t. Virginia sued Maryland, and the case was heard in 2003.
What makes the dispute interesting is that the Supreme Court exercises original jurisdiction when the parties to a suit are states. Normally, the Court exercises only appellate jurisdiction: some other courts have heard and decided the issue first, and the Supreme Court reviews those findings. Here, the Supreme Court was called upon to be the trial court.
Virginia won, by the way.
Suppose the river meandered and changed course for whatever reason. Let’s say for a mile or so it moves 500 feet to the south. Does Maryland gain that land and Virginia lose it? And suppose a Virginia house next to the river now finds itself on the opposite bank. Do the owners lose their Virginiaty and become Marylanders?
Based on what has happened with the Mississippi River, the boundary stays the same. For example, the original capital of Illinois (Kaskaskia) is now on the western side of the river, while the rest of the state is still on the eastern side, because the river moved but the boundary didn’t.