Canada and the Louisiana Purchase

The area covered by the Louisiana Purchase. Ever wonder about that little bit that extends into Canada? Map by William Morris
Parts of Alberta and Saskatchewan have a connection to Napoleon that cannot be claimed by anywhere else in Canada: they were once under Napoleon’s rule.
A question of boundaries
In 1803, short of funds for a planned invasion of England, Napoleon Bonaparte sold Louisiana – France’s territory in mainland North America – to the United States for $15 million. James Monroe (who appears in Napoleon in America) negotiated the purchase.
When it came time to specify the boundaries, there was a slight problem. Most of the land in question had never been explored, surveyed or mapped by a white man. Treaties transferring Louisiana from France to Spain in 1763 and back to France in 1800 had not included a specific delineation of boundaries. Perpetuating this lack of definition, the French representatives agreed to cede to the United States
the colony or province of Louisiana, with the same extent it now has in the hands of Spain, and that it had when France possessed it, and such as it should be after the treaties subsequently entered into between Spain and other states. (1)
When Napoleon was advised of the vagueness of the text, he replied “that if an obscurity did not already exist it would perhaps be good policy to put one there.” (2) He wanted a quick deal, and didn’t mind if the treaty led to conflict between the United States and its neighbours.
Everyone generally agreed that the territory was bordered on the south by the Gulf of Mexico and on the east by the Mississippi River (including New Orleans). The western border with Spain was much disputed. It was eventually fixed as the Sabine River in the Adams-Onís Treaty of 1819.
As for the northern boundary with British North America, that was unclear. France had given up its claims to the area drained by Hudson Bay (Rupert’s Land, nominally owned by the Hudson’s Bay Company) in the 1713 Treaty of Utrecht, though the exact extent of the Hudson Bay land was not defined. When France ceded its colony of Canada to Britain in the Treaty of Paris (1763), the boundary between the Hudson Bay territory and Louisiana remained unspecified.
In October 1802, French Foreign Minister Talleyrand wrote this about the boundaries of Louisiana:
The farther north one goes, the more vague is the demarcation. Since that part of America is without European settlements and encloses only uninhabited forests or Indian tribes, the necessity of marking a line of demarcation has been less felt there. Neither has a line been drawn between Louisiana and Canada. Since both of these countries belonged to France before the treaty of 1763, there was little to be gained in separating exactly their boundaries, and that has not been done since…. (3)
The Missouri and its tributaries
Nonetheless, France believed Louisiana encompassed the watershed of the Mississippi River and its tributaries. According to François Barbé-Marbois, French negotiator of the Louisiana Purchase:
The charter given by Louis XIV to Crozat [the first owner of Louisiana] included all the countries watered by the rivers which empty directly or indirectly into the Mississippi. Within this description comes the Missouri, a river that has its sources and many of its tributary streams at a little distance from the Rocky Mountains. (4)
US President Thomas Jefferson also took this view. On July 11, 1803, he wrote to General Horatio Gates:
The territory acquired…includes all the waters of the Missouri and Mississippi…. (5)
A Cabinet decision of November 14, 1805, regarding the American stance on the western boundary of Louisiana also implied that the northern part of the territory included the tributaries of the Missouri River:
The boundary between the territories of Orleans & Louisiana on the one side & the domns. of Spain on the other shall be the river Colorado from its mouth to it’s source thence due N. the highlands inclosing the waters which run directly or indirectly into the Missouri or Misipi rivers, & along those highlands as far as they border on the Span domns. (6)
Napoleonic Alberta and Saskatchewan?
This is where Alberta and Saskatchewan come in. While most of the rivers and creeks in the southern part of these provinces flow toward Hudson Bay, some – the Milk River in Alberta and the Poplar River and Big Muddy Creek in Saskatchewan – flow south through the Missouri and Mississippi Rivers to the Gulf of Mexico. The lands drained by these tributaries could thus be regarded as having been part of the Louisiana Purchase.

Missouri Territory formerly Louisiana, published by Matthew Carey in 1814. Source: Library of Congress
This can be seen on this 1814 map, which depicts the “Missouri Territory Formerly Louisiana.” In 1812, the state of Louisiana was carved out of the Louisiana Purchase area, and the remaining lands were called the Missouri Territory. The area below the “probable north boundary of the Missouri Territory” encompasses the land around the Missouri River tributaries, including the Milk River and Big Muddy Creek (Martha’s River).

Detail of the previous map, showing the “Probable North Boundary of the Missouri Territory”
The “probable north boundary” soon changed. In the Convention of 1818, Britain and the United States established that the 49th parallel would separate Canada and its southern neighbour from the Lake of the Woods westward to the Stony (Rocky) Mountains – something that the two sides’ negotiators had agreed on in 1807.
As for how long parts of present-day Alberta and Saskatchewan were – at least in theory – under Napoleonic rule, the answer is not long. Although France had secretly acquired Louisiana from Spain in 1800, Spain continued to administer the territory. To effect the transfer of the Louisiana Purchase to the United States, France took control of Louisiana on November 30, 1803. The French handed Louisiana over to the Americans just three weeks later, on December 20, 1803.
If you wonder what might have happened if Napoleon had tried to play a greater role in ruling parts of North America, read Napoleon in America.
You might also enjoy:
Were there Canadians at the Battle of Waterloo?
A Tomb for Napoleon’s Son in Canada
- Louis Houck, The Boundaries of the Louisiana Purchase: A Historical Study (St. Louis, 1901), p. 5.
- François Barbé-Marbois, The History of Louisiana: Particularly of the Cession of that Colony to the United States of America (Philadelphia, 1830), p. 286.
- James Alexander Robinson, Louisiana Under the Rule of Spain, France and the United States, 1785-1807, Vol. 2 (Cleveland, 1911), p. 141.
- The History of Louisiana: Particularly of the Cession of that Colony to the United States of America, p. 290.
- Thomas Jefferson Randolph, Memoirs, Correspondence, and Private Papers of Thomas Jefferson, Vol. III (London, 1829), p. 518.
- Paul Leicester Ford, The Works of Thomas Jefferson, Vol. X (New York and London, 1905), p. 180.
24 commments on “Canada and the Louisiana Purchase”
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Since that part of America is without European settlements and encloses only uninhabited forests or Indian tribes, the necessity of marking a line of demarcation has been less felt there. Neither has a line been drawn between Louisiana and Canada.
Talleyrand
Interesting article
Thanks, Mark.
Thanks Shannon. Looking back today is seems rather strange that no one involved in the sale considered there were humans living on this land. They had been there making their living from it for thousands of years; if anyone had a MORAL claim to the land, they did. They were the natural owners. Nonetheless, I am glad US and UK did not go to war with one another later over that little patch that fell into Canada. Sanity for once.
I agree, Addison. Talleyrand’s comment about the territory containing “only” Native Americans was quite reflective of the prevailing attitude.
Didn’t really answer the question but I reallllllllly liked this site
Thanks, Sydney.
Hi, I’m trying to figure out what modern Canadian cities would have been part of the Louisiana purchase. Lethbridge? Medicine Hat? Swift Current, Moose Jaw? It’s just too hard to tell on these ancient maps. Can you help?
Here’s a map of the Missouri River watershed that might help, Vince: https://en.wikipedia.org/wiki/List_of_tributaries_of_the_Missouri_River#/media/File:Missouri_River_basin_map.png. There is also this map of the Milk River watershed: https://caringforourwatersheds.com/canada/southern-alberta/watershed-information; and this map of the Poplar River watershed: https://www.ijc.org/en/watersheds/poplar-river; and this map shows the watersheds of all three of the Missouri River tributaries in Saskatchewan (Milk River, Poplar River, Big Muddy Creek): http://caringforourwatersheds.com/wp-content/uploads/2013/12/Watershed-Map-and-Contact-Information-Updated-May-2015.pdf.
All of the cities you mention look like they’re too far north. Assiniboia appears to be the largest town in the area, followed by Milk River, Coronach and Eastend.
Great! Thanks for posting. Love history!
Thanks, Willy. Glad you enjoyed the post.
… Hi Shannon: … I am wondering where the Dakota Nation(also Nakotas, Lakotas) fit into this history?
Hi Rudi. That’s something I’ve not looked into. Obviously it involved their land, but I don’t think anyone associated with the deal even considered that.
Very interesting Shannon-an unusual snippet of Canadian history, informative, many thanks from the UK. I was in Canada a long time ago & am interested in the history of your country!!! ps Stay safe in these strange times of Covid 19!!!
Thanks, Tony. You too!
Interesting article. Just imagine had Napoleon had won against Horatio Nelson at the Battle of Trafalgar, especially with the Spanish at his side!
By the way, Weyburn is more than three times the size of Assinaboia.
Thanks, Balkrishna. You’re right, Weyburn is much larger than Assiniboia, although it falls in the Upper Souris River watershed, so it was not part of the Louisiana Purchase. If you like Napoleonic “what ifs,” you might enjoy my article on Napoleon in alternate history: https://shannonselin.com/2014/11/napoleon-alternate-history/.
I was born in Alberta in 1947 and did not know this about our provincial history. Thank you for this great site!
You’re welcome, Stew. Glad you enjoyed the article.
Great article Ms. Selin. Crazy to think everything south of Lethbridge was once Spanish/French territory. WOW! MIND BLOWING!
Thanks, Jim. As someone who was born and raised in Saskatchewan, I think that’s pretty neat too!
Thank you for this! I grew up in Shaunavon, down the road from Eastend. I didn’t know the land my town is on was part of the Louisiana Purchase. I only found out while I was in New Orleans and saw the map. I would love to find a modern map with the LP purchase border overlaid on it.
You’re welcome, Ryan. Here’s a link to the map I used at the top of the post (from Wikimedia Commons): https://commons.wikimedia.org/wiki/File:Louisiana_Purchase.jpg. I haven’t come across a modern map that provides more detail. It would be great to find one that makes it easy to see which Canadian towns are on land that fell within the Louisiana Purchase.
Hi Shannon. Since Canada purchased Rupert’s land, which would have been all lands flowing into Hudson’s Bay, can it not be argued conversely that portions of North Dakota and Minnesota would have been ceded to Canada if not for the 1807 agreement on the 49th parallel? I’m thinking of course of the Red River. I do realize the Rupert Land purchase for Canada was in 1869. But it is another interesting ‘What if’.
Thanks for this very interesting point, Jeff. You’re right, that would make a great ‘what if’!