The Complete Harvard Classics - ALL 71 Volumes: The Five Foot Shelf & The Shelf of Fiction: The Famous Anthology of the Greatest Works of World Literature

by Charles William Eliot

"His disorder, which proved the small-pox, increased speedily upon him,

Smallpox Incubates 7-19 days , so he isn't carrying this infection from its incidence in Mt. Holly the previous winter. He must have been exposed during his travel in England.