A series in which I gently suggest that I’m not the only person to be frustrated, though it certainly feels that way.
Quebec Smallpox Epidemic of 1776

Why isn’t Quebec part of the United States? Yes, it’s due to one of your favorite Terrible Things: smallpox.
Notorious baddie Benedict Arnold was up north in the winter of 1775-6. The rebels were trying to push the British back, and to add more territory to these United States, too, I guess. They had already won Montreal. They had about 2,500 soldiers, and about a third of them came down with smallpox.
Some might say rebels got smallpox from seductresses of the north, wily women who deliberately lay with American troops in order to infect them.
But maybe that’s just what those filthy disloyal American sluts claimed. I’m not sure.
British troops were much less affected by smallpox. Many of them had already had the disease and survived, or had been vaccinated.
American soldiers tried to inoculate themselves. Smallpox inoculation had been used since as early as 500 BCE in some places, but all the kinks weren’t worked out. Their attempts at inoculation often resulted in contracting a full-blown case of smallpox.
Thus General John Thomas ordered them not to try to self-inoculate. And then he died of smallpox.
In July 1776, another historical item of note was that the Americans left Canada, not because they were outgunned or outfoxed, but because smallpox had hit them so much harder. A huge number of American soldiers were killed by smallpox, rather than by British troops.
George Washington happened to have contracted smallpox on his only overseas trip, to Barbados. Going against an agreement of the Continental Congress, he ordered American troops to be inoculated in 1777.