The North West Angle: how a 1783 screw-up left chunks of US territory marooned in Canada

Spot the deliberate mistake. Image: Google.

Last week I wrote a faintly ranty piece listing 13 things about the map of the US that wind me right up. A lot of people on Twitter pointed out that I'd missed a good one. So...

It's 1783. The American War of Independence is coming to a close, everyone is knackered, and among the many pressing questions facing those drawing up the peace treaty is that of the new nation's northern boundary: where United States territory stops, and British North America begins. This challenge is made all the more difficult by the fact that, west of the Great Lakes, everyone's knowledge of the region's geography gets just a little bit hazy.

But, the negotiators do what they must, and the Treaty of Paris states that the boundary will run:

“...through the Lake of the Woods to the northwestern-most point thereof, and from thence on a due west course to the river Mississippi.”

Back in 1783, the land west of the Mississippi was French territory, so this seemed to settle the matter: find the northwestern-most point of the lake, draw a line west until you hit the river, and then you’re sorted.

How you calculate the northwesternmost point of a lake: it involves drawing a lot of lines from north east to south west. Image: Strafpelaton 2/Wikimedia Commons.

There was just one problem: despite what the maps of that era showed, west of the Lake of the Woods, there was no River Mississippi. The then unknown source of the river was Lake Itasca, in the north of Minnesota about 180km south of the Lake of the Woods.

The red pin marks the source of the Mississippi. Note that it is a surprisingly long way from Canada. Image: Google.

Later treaties would correct this somewhat, by placing the boundary to the west at the 49th parallel (that's the long straight line at the top of maps of the US). To the east, though, it was already established, so the stuff about the northwestern-most point of the Lake in the Woods stayed: the two bits of the border were linked by a straight line running north-south.

The result was a border that looks like this:

Image: Google.

Spot anything odd about that border?

Image: Google.

See it now? Here's another map, from Wikipedia.

Image: The Illusional Ministry/Wikimedia Commons.

That looks weirdly like the top right corner of the map is actually an inset, a larger version of something else on the map. It's not: it's just a part of Canada (Manitoba, to be specific) with square boundaries.

And, because those boundaries are so straight, a couple of bits of land have been cut off, and ended up in the United States.

The larger is the Northwest Angle: home to around 120 Minnesotans, who can't reach the rest of the state without either crossing a lake or going through Canada. It's only 319km2, which isn't very big; but that’s still around twice the size of Washington DC, so it’s not that tiny either.

The other cut off is Elm Point, a small cape which isn't home to anyone at all, but is nonetheless considered US territory. Both of these, incidentally, are “practical exclaves” of the US: portions of territory that can’t be reached by land without going through someone else’s country. (They’re not enclaves because Canada doesn’t completely surround them.)

None of this really matters in practical terms since the US-Canada border is one of the most permeable in the world. There's not talk of building a wall here (wonder why) though you are, technically, meant to phone customs as you cross the border to make your declaration.

But it does teach an important life lesson: don't define boundaries on the basis of a river without checking where that river actually goes first.

For more stories of silly boundaries, click here.

Jonn Elledge is the editor of CityMetric. He is on Twitter, far too much, as @jonnelledge.

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CityMetric is now City Monitor! Come see us at our new home

City Monitor is now live in beta at

CityMetric is now City Monitor, a name that reflects both a ramping up of our ambitions as well as our membership in a network of like-minded publications from New Statesman Media Group. Our new site is now live in beta, so please visit us there going forward. Here’s what CityMetric readers should know about this exciting transition.  

Regular CityMetric readers may have already noticed a few changes around here since the spring. CityMetric’s beloved founding editor, Jonn Elledge, has moved on to some new adventures, and a new team has formed to take the site into the future. It’s led by yours truly – I’m Sommer Mathis, the editor-in-chief of City Monitor. Hello!

My background includes having served as the founding editor of CityLab, editor-in-chief of Atlas Obscura, and editor-in-chief of DCist, a local news publication in the District of Columbia. I’ve been reporting on and writing about cities in one way or another for the past 15 years. To me, there is no more important story in the world right now than how cities are changing and adapting to an increasingly challenging global landscape. The majority of the world’s population lives in cities, and if we’re ever going to be able to tackle the most pressing issues currently facing our planet – the climate emergency, rising inequality, the Covid-19 pandemic ­­­– cities are going to have to lead the way.

That’s why City Monitor is now a global publication dedicated to the future of cities everywhere – not just in the UK (nor for that matter just in the US, where I live). Our mission is to help our readers, many of whom are in leadership positions around the globe, navigate how cities are changing and discover what’s next in the world of urban policy. We’ll do that through original reporting, expert opinion and most crucially, a data-driven approach that emphasises evidence and rigorous analysis. We want to arm local decision-makers and those they work in concert with – whether that’s elected officials, bureaucratic leaders, policy advocates, neighbourhood activists, academics and researchers, entrepreneurs, or plain-old engaged citizens – with real insights and potential answers to tough problems. Subjects we cover include transportation, infrastructure, housing, urban design, public safety, the environment, the economy, and much more.

The City Monitor team is made up of some of the most experienced urban policy journalists in the world. Our managing editor is Adam Sneed, also a CityLab alum where he served as a senior associate editor. Before that he was a technology reporter at Politico. Allison Arieff is City Monitor’s senior editor. She was previously editorial director of the urban planning and policy think tank SPUR, as well as a contributing columnist for The New York Times. Staff writer Jake Blumgart most recently covered development, housing and politics for WHYY, the local public radio station in Philadelphia. And our data reporter is Alexandra Kanik, whose previous roles include data reporting for Louisville Public Media in Kentucky and PublicSource in Pittsburgh, Pennsylvania.

Our team will continue to grow in the coming weeks, and we’ll also be collaborating closely with our editorial colleagues across New Statesman Media Group. In fact, we’re launching a whole network of new publications, covering topics such as the clean energy transition, foreign direct investment, technology, banks and more. Many of these sectors will frequently overlap with our cities coverage, and a key part of our plan is make the most of the expertise that all of these newsrooms combined will bring to bear on our journalism.

Please visit going forward, where you can also sign up for our free email newsletter.

As for CityMetric, some of its archives have already been moved over to the new website, and the rest will follow not long after. If you’re looking for a favourite piece from CityMetric’s past, for a time you’ll still be able to find it here, but before long the whole archive will move over to City Monitor.

On behalf of the City Monitor team, I’m thrilled to invite you to come along for the ride at our new digs. You can follow City Monitor on LinkedIn and on Twitter. If you’re interested in learning more about the potential for a commercial partnership with City Monitor, please get in touch with our director of partnerships, Joe Maughan.

I want to thank and congratulate Jonn Elledge on a brilliant run. Everything we do from here on out will be building on the legacy of his work, and the community that he built here at CityMetric. Cheers, Jonn!

To our readers, on behalf of the City Monitor team, thank you from all of us for being such loyal CityMetric fans. We couldn’t have done any of this without you.

Sommer Mathis is editor-in-chief of City Monitor.