When the first sod was turned near Cornwall, Ont., August 10, 1954, it was not so much the beginning of the great St Lawrence Seaway as a continuation of centuries of dreams.

Both Jacques Cartier and Samuel de Champlain looked with as much hope as despair over the rapids just west of Montreal. Daydreaming that the riches of China lay just beyond, the French called them "La Chine." The Sulpician priest Dollier de Casson was the first to express the idea of building a small canal to circumvent the rapids in 1680. One Gideon de Catalogne went so far as excavating a canal in 1700, but he went bankrupt only a few hundred metres from completion.

Soo Locks at Sault Ste Marie (Colour Library Books)

In 1781 the British, ever wary of American intentions along the border, imported a group of Cornish miners to quarry four small canals along the St. Lawrence River. These shallow canals, along with the first Lachine Canal in 1825, and the Cornwall Canal in 1843, facilitated the movement of narrow-draft bateaux from Lake Ontario to Montreal.

Beyond the St. Lawrence, the greatest obstacle to navigation on the Great Lakes was obviously Niagara Falls. With great ingenuity and ambition, Upper Canada completed the first Welland Canal in November 1829. Forty locks raised or lowered the vessels some 91 metres. The Welland Canal was rebuilt in 1887 and again, on a gigantic scale, from 1913 to 1932. Now that larger "upper lakers" could carry cargo from Lake Superior to Lake Ontario, the St Lawrence canals stood out as a major bottleneck.

In 1871 the new Canadian government undertook to rebuild all existing canals to accommodate larger vessels. In one of the largest public works undertaken in Canada till that time, all canals and locks were enlarged to 14-foot (4.2 metre) depth. These canals served Canada and the United States until the 1950s. Many steamship companies had ocean-going vessels built to enable them to use the 14-foot locks. For the inland trade a fleet of some 200 ships was built to carry ore and grain.

Although the building of the modern Seaway in the 1950s is cited as a great co-operative venture between Canada and the United States, the Americans were in fact reluctant partners. There was strong opposition from the Atlantic ports, Texas ports, railway interests and others. Lobbyists persuaded the US Senate to reject a Seaway plan in 1932.

In Canada it was clear that the St. Lawrence bottleneck was an impediment to economic growth, especially after rich deposits of iron ore had been discovered in Labrador. In 1951 Prime Minister Louis St. Laurent succeeded in twisting President Harry Truman's reluctant arm by telling him that if the Americans did not want to help build the Seaway, Canada would build it alone.

Once construction began however, the Americans acted, as Lionel Chevrier wrote, as if "they were responsible for doing the whole job." President Eisenhower, who during negotiations told Chevrier that Canada would "be better off as the 49th state," wanted to take complete control of the International Rapids section. Prime Minister Pearson replied that in that case, Canada would build its own canal and locks there as well. The US relented. (In the end, Canada footed 75% of the bill for the Seaway.)

The completion of the Seaway in only five years was a phenomenal engineering and construction achievement. Some 500 engineers and 22 000 workers completed the work in half the time it took to build the Suez Canal, which has no locks.

Among the special problems faced by the engineers was what to do with the bridges over the St. Lawrence River. Those at Cornwall were simply replaced. The Jacques Cartier Bridge at Montreal had to be slowly jacked 15 metres higher. The venerable Victoria Bridge could not be jacked up, however, and the CNR, who owned it, refused to allow any interruptions in traffic. Finally an ingenious solution was found by building an extension to the south end of the bridge so that traffic could be diverted to one side or other of the lock as a ship passed.

The Canadian Coast Guard icebreaker d'Iberville, was first vessel to enter the St. Lambert lock, on April 25, 1959. The Royal yacht Britannia sailed in June 26, carrying Queen Elizabeth and President Eisenhower. The two officially opened the Seaway that day.

James H. Marsh is editor in chief of The Canadian Encyclopedia.