June 26, 1959: The Queen and US President Dwight D Eisenhower have inaugurated the 2,300-mile St Lawrence Seaway in Canada that links the Atlantic with the Great Lakes in North America.
Crowds cheered and waved flags, church bells rang out, sirens wailed and bands played as the Royal Yacht Britannia began the first leg of the journey from Montreal harbour to the Atlantic Ocean.
On board were the Queen, representing Canada, and President Eisenhower who could be seen chatting together on deck and waving to the crowds.
Balloons and fireworks were released when the ship's bow passed a symbolic gate at St Lambert Lock made of old timbers from the lock of the Lachine canal which was built to bypass the Lachine rapids. The seaway takes a different route avoiding the rapids and rendering the Lachine canal obsolete.
Then all the whistles and sirens of ships in Montreal harbour went off.
'In love with the Queen'
At one point an American congressman called to the president from the lock side: "We have all fallen in love with the Queen, Ike!"
Earlier, the Queen as head of the Commonwealth welcomed President Eisenhower to Canada at Montreal airport.
After inspecting a Royal Canadian Air Force guard of honour they took an open-top car to the St Lawrence River.
There the two heads of state were each presented with a commemorative book with the names of the men who built the seaway.
The Queen then made a speech welcoming the president and his wife to Canada to mark the inauguration of a "great joint enterprise between our two countries".
She acknowledged the project would open up the centre of America to world trade and enhance Canadian commerce in the process.