The new waterway began operating in the spring of 1959 and was an immediate success. Traffic grew from 25 million tonnes in that first year to more than 70 million tonnes annually by the late 1970s. Most of the cargo consisted of bulk commodities such as grain, iron ore, coal and construction aggregates. The seaway proved indispensable in moving export-bound Prairie grain from Thunder Bay to the lower St. Lawrence and iron ore from the mines of western Labrador and eastern Quebec to steel plants in Hamilton, Sault Ste. Marie and elsewhere on the Great Lakes. The system was so heavily used in the first 10 years that the Welland Canal became a serious bottleneck and dozens of ships were frequently lined up at both ends awaiting passage. The big problem was a 14.5-kilometre long stretch of the canal that passed through the city of Welland. There were too many turns, as well as six bridges to be lifted or swung open every time a ship passed.
The solution was the Welland Canal Bypass, which was built between 1968 and 1973 at a cost of $188 million. It was straighter, wider and deeper and allowed the entire seaway to keep pace with the extraordinary demand created by the booming economies of Canada and the U.S. In 1979, the seaway’s 20th year of operation, 74.3 million tonnes of cargo moved on the waterway, a record unsurpassed to this day.
This interactive timeline delves into the history of the St. Lawrence Seaway, beginning in 1779, and showcases the evolution of the Seaway’s construction and operation, leading up to its anniversary celebration in 2009. Users can select which era they wish to learn about by clicking on a specific year, each with its own image and explanation.