A near-contiguous waterway stretching halfway across the widest part of the continent massively accelerated North American development. Hugh de Lacy reflects.
While other countries relied on trains of both the wagon and the rail variety to open up their interiors from the 18th century onwards, Canada and the United States had the head start of boat transport into their interiors, thanks to the St Lawrence River and the five Great Lakes.
The impetus that this gave both countries’ economies in the couple of centuries following first European contact was one of the single most important factors in their rapidly overtaking the wealth of the European empires that colonised them.
But it wasn’t as easy to exploit that natural waterway as it would appear on maps of the continent: with a succession of portages, explorers in canoes could travel the 3700 kilometres from the Ile d’Anticosti on the Atlantic Ocean to the head of Lake Superior, but anything bigger found its way blocked by swamps, waterfalls and rapids at many points.
The first efforts to make the river navigable began in 1783 with the digging of shallow canals that allowed the long, tapered, flat-bottomed boats of the French to access the eastern-most of the Lakes, Ontario.
Construction gathered pace in the 19th century with the 584 kilometre Erie Canal and its 34 locks carved out between Buffalo, New York, and the Hudson River between 1817 and 1825, giving access to both the river and the sea.
Then between 1824 and 1829 the Province of Upper Canada built the Welland Canal, linking lakes Ontario and Erie through a series of eight locks that allowed ships to descend the Niagara Escarpment and bypass the 51 metre-high Niagara Falls.
No fewer than four further canals were added to the Welland system over the next 150 years, with that work continuing right up until a couple of years ago.
The early works served to whet the appetite for establishing sea-going ship access all the way to Lake Superior, the western-most of the five Great Lakes, but it soon became clear that the Canadians and the Americans had conflicting ideas about it.
In 1913 Canada openly declared the goal of just such a seaway, and tapped the Americans for a contribution to the cost.
Perhaps surprisingly, the Americans demurred, not just then but again in 1932 when Canada proposed a Seaway Treaty to the get the work under way.
The American fear was that the seaway would suck development investment northwards from its own established north-eastern economic centres, thereby benefitting Canada more than the United States.
The Americans relented somewhat in 1941 but they didn’t ratify a second treaty to build the seaway until 1954, and then only because it was apparent the Canadians were going to go ahead with the project anyway.
The only way for the Americans to protect their existing interests, and to extract any benefit or control along their northern border, was to buy into the seaway project.
A lesser incentive in what became a Joint International Commission to get the work under way was that Canada also intended to build a big hydro-electric installation, the Moses-Saunders Power Dam, as part of the seaway.
The dam required bilateral cooperation because it would lower the water level in the river, affecting both countries, so eventually it became the joint responsibility of Ontario Province and New York state.
Hydro-electrical generation had been seen as an important element in the overall project from as early as the 1900s, with dams serving the twin roles of controlling the river flow and turning it into the new phenomenon of electrical power.
The principal opponents of the seaway were the American Atlantic seaports, the railways and the Canadian city of Quebec, all of which feared losing existing business, but eventually Canadian Prime Minister Louis St Laurent managed to stir up nationalistic enthusiasm for the project, and then persuaded President Harry S. Truman to bring the US aboard.
Canada’s Parliament in 1951 created the St Lawrence Seaway Authority to run its side of the operation, while the Americans established their St Lawrence Seaway Development Corporation.
World War Two was still fresh in Americans’ minds, and in 1957 the United States Army Corps of Engineers, rather than a private contractor, was given the job of building the Connecting Channels Project which made access to the interior feasible.
Seven locks were separately constructed on the St Lawrence River portion of the seaway, adding to the eight on the Welland Canal.
The cost of the wider project, including the Moses-Saunders dam, was high – US$6 million – but by the middle of 1959 deep-draft ocean-going ships could travel all the way to Duluth, Minnesota, at the extreme western end of Lake Superior.
The first vessel to go through the locks constructed by the US Army was the US Coast Guard cutter Maple.
When the Eisenhower administration succeeded Truman’s, all American reluctance to join with Canada in exploiting and expanding the seaway faded away, and he joined the recently crowned Queen Elizabeth II on her yacht Britannia for a short cruise that formally opened the seaway in 1959 amid much enthusiasm from both countries.
Perhaps surprisingly, the seaway locks are smaller than those on the Panama Canal, completed by the Americans in 1914, with capacity for ships of 289.56 metres by 32.31 metres, known as the Panamax Limit. Subsequently, the New Panamax limits (from 2016) are 366m by 51.25m.
The seaway’s locks were built to accommodate ships of only 230m long by 24m wide, known as the Seawaymax Limit, principally because that was the size of the existing locks on the Welland Canal.
Not unexpectedly, the seaway’s opening doomed the old Erie Canal to virtual redundancy, and severely affected the economies of a string of American cities along its banks.
Elsewhere though the seaway proved a massive economic boon to both countries over the second half of the 20th century, and today it generates nearly US$4 billion in annual business revenue in the US alone, with most of the inbound cargo comprising steel, and the outbound comprising grain.
But while the St Lawrence Seaway will always stand as one of man’s greatest engineering feats, its economic value has faded over the past couple of decades, primarily because of changes in the world grain market.
Europe is no longer the great grain destination it used to be, and it’s the North American continent’s West Coast ports that are handling such cargo now bound for South America, Asia and Africa.
But however reduced it may be in economic importance, the St Lawrence Seaway will always be more than just a border between Canada and the United States.