In a letter written on February 16, 1759 to an English friend, Benjamin Franklin described the practice of inoculation for smallpox in Boston as follows:
Inoculation was first practiced in Boston by Dr. Boylston in 1721 . It was not used before in any part of America, and not in Philadelphia till 1730. Some years since an enquiry was made in Philadelphia of the several Surgeons and Physicians who had practised Inoculation, what numbers had been by each inoculated, and what was the success. The result of this enquiry was that upwards of 800 (I forget the exact number) had been inoculated at different times, and that only four of them had died. If this account was true, as I believe it was, the reason of greater success there than had been found in Boston, when the general loss by Inoculation used to be estimated at about one in 100, may probably be from this circumstance, that in Boston they always keep the distemper out as long as they can, so that when it comes, it finds a greater number of adult subjects than in Philadelphia, where since 1730 it has gone through the town once in four or five years, so that the greatest numbers of subjects for inoculation must be under that age.
Notwithstanding the now uncontroverted success of Inoculation, it does not seem to make that progress among the common people in America, which was at first expected, Scruples of conscience weigh with many, concerning the lawfulness of the practice, and if one parent or near relation is against it, the other does not choose to inoculate a child without free consent of all parties, lest in case of a disastrous event, perpetual blame should follow.