'Records from Boston, starting in 1811, reveal recurring smallpox epidemics beginning around 1837. Despite the introduction of vaccination mandates in 1855, epidemics continued to occur in 1859 to 1860, 1864 to 1865, and 1867, with a particularly severe outbreak from 1872 to 1873. The continual reoccurrence of these epidemics in Massachusetts indicates that stringent vaccination regulations had no positive impact on curbing smallpox.

According to the research article, “SmallPox and Revaccination,” published in the 1881 Boston Medical and Surgical Journal, “The latest epidemic that of 1872–1873, having proved fatal to 1,040 persons, was the most severe (https://list.mailexpress.com/l....inks/xr4kR500zI~331/ that has been experienced in Boston since the introduction of vaccination.”
 
In Chicago, despite 95 percent vaccination coverage by 1868 and mandatory vaccination after the Great Chicago Fire of 1871, a severe smallpox epidemic occurred in 1872. Over 2,000 people contracted smallpox, and more than a quarter of these died (https://list.mailexpress.com/l....inks/xr4kR500zI~331/ with the highest fatality rate among children under age 5.
Europe: No Decline After Vaccination
Throughout the Western world, epidemics were more severe in highly-vaccinated populations.
 
Dr. G. W. Harman published an article in the 1900 medical journal Medical Brief (https://list.mailexpress.com/l....inks/xr4kR500zI~331/
entitled “A Physician’s Argument Against the Efficacy of Virus Inoculation,” highlighting widespread smallpox cases among vaccinated individuals in England, France, and Germany.

The death rate for smallpox declined after 1872, but there is no evidence that vaccination had anything to do with it. In the early 1900s, death from smallpox all but vanished from England...'