Epilogue: Defeated by disease

Although we get along quite well now with those south of the longest undefended border in the world, relations between Canadians and Americans have not always been so cordial.

In 1812 and a few decades before, during the American Revolution, Canadians fought their Yankee neighbours in fierce and bloody battles. I had learned the facts of these conflicts as a schoolboy. To this day I continue to be proud that the White House is so named because British troops burned it during the War of 1812 and it required a good coat of paint to cover up all the scorch marks.

As well, I was taught that in September 1774, the Continental Congress appealed to us in an open letter to join the colonies rebelling against the British.

The Americans even sent agents to Montreal advocating rebellion and hoping that they would persuade the Canadians to cross over.

What I hadn't realized, at least until I came across a fascinating article published in the Annals of Internal Medicine, was that if it hadn't been for smallpox, we would most likely today be in the midst of a presidential election, enjoying a strong dollar and living with the National Rifle Association.

The story is one more example of how disease can -- and sometimes does -- alter history. The tale begins in 1775 with the Americans sending two military expeditions north. One group, under General Bernard Montgomery, debarked from Fort Ticonderoga in New York State in order to seize Montreal. The other, commanded by General Benedict Arnold (before he turned coat), marched through Maine toward Quebec City. Although Montgomery captured Montreal, fortunately for Canadian history, his diplomatic skills were far less refined than his military abilities.

After imprisoning Canadians who would not agree to collaborate with the American invaders, he then foolishly (given that in the 1774 Quebec Act the victorious British had guaranteed the Canadians -- Québécois today -- freedom of worship) ordered the churches closed. As if these acts weren't damaging enough from a diplomatic point of view, Montgomery's soldiers introduced smallpox into the city, making the Americans even less welcome guests.

In an attempt to practise some belated damage control, Benjamin Franklin was sent to Montreal, where he wisely released the prisoners and reopened the churches. But the damage had been done. In the end, his mission failed and the Canadians never agreed to join the fight against the British. Meanwhile, Arnold's soldiers failed in their attempts to capture Quebec City, and having been forced back, they withdrew up the St. Lawrence, waiting to coordinate a further attack with Montgomery's more successful soldiers. Montgomery's troops, however, not only infected the citizens of Montreal, they also brought the disease into the camp of their colleagues besieging Quebec City.

How did the British and Canadian soldiers fare? Much better, because the army was protected by a higher rate of natural immunity given the higher incidence of the disease in crowded England compared with the much more spread-out population of the colonies.

And unlike the Americans, the British Army had a policy of vaccinating recruits. Their soldiers went through the entire campaign with only a few cases of the disease. (Our vaccination rates con-tinue to be higher to this day.) It was a different story for the Americans. By May 1, 1776, nearly half of the soldiers confronting Quebec City were ill with smallpox caused by an especially virulent strain that resulted in a very high fatality rate.

This catastrophic turn of events forced the Americans to suddenly raise the siege, admit defeat and retreat with their sick to the shores of Lake Champlain.

As American officer Charles Cushing wrote, "We have now been at Crown Point for eight days and since then have buried great numbers from the smallpox. Some regiments which did not inoculate have lost as much as a third of their number."

And a member of Congress also wrote: "Our misfortunes in Canada are enough to melt a heart of stone. The smallpox is ten times more terrible than the British, Canadians and Indians together. This was the cause of our precipitous retreat from Quebec."

Washington finally did decide to vaccinate the Northern Army. By August 1776 the epidemic was stopped in its tracks, but it was too late. With the ice gone from the St. Lawrence, the British navy had brought in significant reinforcements for the Quebec garrison and further colonial attack would have been doomed.

It seems clear that smallpox (and in particular the difference in the British and American armies' views on vaccination) in the end decided Canada's fate. Without the outbreak of this particular epidemic and its totally enfeebling effect on the colonial army at exactly the right time and right place, the greater part of Canada -- if not all of it -- might well now be in American hands.

Dr. A. Mark Clarfield is head of Academic Affairs at the Sarah Herzog Hospital in Jerusalem and a staff physician in the Division of Geriatric Medicine of the McGill-affiliated Sir Mortimer B. Davis-Jewish General Hospital in Montreal.