That’s why I said “supposedly”. But I don’t think that even Congress has the power to establish where the Continental Divide is 
Reality does not always stop politicians when it tries to get in the way.
The Merrimack River. There are definitely curves to the border, too.
The border becomes a straight(ish) line heading west(ish) from the point three miles south of the southern most point of the Merrimack. The odd squiggle between New Hampshire and Massachusetts is the 3-mile offset.
The same thing happens with the Charles River on the south border of Massachusetts (Rhode Island and Connecticut), only there isn’t a squiggly part. The border is a line of latitude offset from what was understood to be the southern most point of the Charles River. The Charles is more famous for being the river that empties into Boston Harbor, but it starts well inland and meanders as a narrow stream through eastern Massachusetts.
The comment makes no sense because the boundary was the Bitterroot Range and not the Continental Divide.
It is true that the divide was, at least partially, following the Bitteroot Range. It’s true that the border also follows the range. But it’s not true that the Divide was established by act of Congress.
They didn’t attempt to. This was a myth repeated here by someone who failed to do a simple fact check.
And no one said they did.
I mean, yeah, I get that that’s not what you meant, but what you said was
[quote=“Crafter_Man, post:83, topic:1012484”]
[Some states came very close to war over border disputes]( Toledo War - Wikipedia ).
Michigan got the last laughs, with getting the UP and all
[/quote]
As a native Detroiter, I have on more than one occasion amused myself by asking non-Michiganders * if they have heard of the Toledo War. And if they look confused, I add “Wisconsin lost.” **
Ohioans know what I am talking about. Nobody else usually does.
* It was “Michiganders” when I was a kid so it is always Michiganders, dammit.
** Ohio got the Toledo strip, and Michigan annexed the UP from Wisconsin. WI was just a hapless bystander.
Foe this reason, if you look closely, the southern MI border is not straight. It makes a dogleg north around the aforementioned Toledo strip.
If you want to be snarky about the UP, you could say Wisconsin won.
Ha! True. They do call us trolls, after all (we live below the bridge) so a little snark is not uncalled for.
I don’t think that anyone answered this but I would be extremely surprised if the various borders within and around the US haven’t been resurveyed many times, not to shift their physical location but to better record where they are.
It’s unlikely that any borders will be shifted due to better survey fix any time soon since as far as I’m aware none of the remaining territorial disputes focus on this issue. When these borders were marked out, both parties had to accept the results on the ground as acceptable (or dispute it). So while the common description of the boundary might be the 49th parallel, it’s more likely that the real description will be something along the lines of ‘the 49th Parallel, as measured by Y’s resurvey of the positions monumented by X’s original survey.’
After all, it’s never possible to get it spot on. You can always get out your micrometer or electron microscope and claim the line deviates. Since there’s no global surveyor-general defining tolerances and regulations for this sort of thing, the parties have to agree by treaty. Once the marked line is acceptable a much more precise record will likely be made of it than the principles that originally guided the definition.