Onesimus: The Enslaved African Who Introduced The Method Of Vaccination During The Smallpox Epidemic


In 1704, a young slave was carried abroad in the Bance Ifland vessel from the Windward & Rice coast, arriving in Boston, Massachusetts on May 6th. Nothing was known about this; thus his birth name, age and date of birth were not recorded upon his capture. From his native tongue, it was concluded that he was of the Akan, the dominant ethnic group in modern Ghana.

In December 1706, after two years of living in the colonies, he was gifted to Cotton Mather, a Puritan Minister, by the congregants of the North Church. Mather named the slave Onesimus, after a first century slave cited in the book of Philemon in the Bible. In Mather’s household, Onesimus proved to be highly intelligent as compared to other slaves and Mather began to instruct him in reading and writing.

Cotton Mather.
Corbis/Getty Images

In 1716, in one of their conversation which left Mather intrigued by Onesimus smartness he asked Onesimus if he had ever contracted smallpox.  He replied in the affirmative and negative and before Mather could muse over this answer, Onesimus began to describe the procedure performed in his native land. The procedure involved rubbing of pus from the vesicles of an infected person into a fresh wound of an uninfected person. He also stated that any who was brave to undergo the procedure could be rest assured of never catching the disease. Onesimus then showed a scar on his arm proving that he had undergone the procedure.

After the smallpox episode, Mather began research on variolation of the terminology for the procedure Onesimus had explained. He realized that the procedure was practised amongst the indigenes of Sub-Saharan Africa for ages. The procedure was still prevalent amongst the black slave communities in the Americas.

Finally, a questionnaire with other slaves verified Onesimus’ story. After concluding his findings, Mather sent a letter to the Royal Society of London recommending the procedure for smallpox treatment. He received a massive backlash from the public who saw him dumb to accept recommendations from a slave. They were more adamant to accept the procedure as it was believed to be a scheme of the Africans to poison and overthrow the white citizens.

Onesimus married a woman of African descent whilst he was still serving Mather’s household.  Mather, probably out of admiration and respect, allowed Onesimus to receive an independent wage. He would beget two children, both dying before celebrating their tenth birthday. All this while Mather, realizing that Onesimus would have been a channel to introduce the Puritan beliefs to enslaved Africans, decided to convert him.

However, no matter how hard he tried, Onesimus vehemently rejected.  He would attempt to purchase his freedom by raising money to get another slave named Obadiah to replace. Mather would later give him a ‘special freedom’, compelling him to render services to the household only upon command.

In 1721, Boston experienced a smallpox epidemic and Zabdiel Boylston, a physician decided to ignore all unsubstantial claims against Onesimus’ method and put it to test, using it on his patients. He first tried the procedure on his six-year son and two of his slaves. When all seemed well after the initial tests, he went on to inoculate about 280 people and recorded only six deaths in the yearlong smallpox epidemic in Boston. Seventy-five years later, a vaccine based on the concept of Onesimus’ procedure would be developed by Edward Jenner in 1796.

Just like his birthdate and place, the death of Onesimus is unknown to the world, but his involvement in inoculation is a fact which cannot be ignored.

Fun facts: In 1980, the World Health Organization declared smallpox totally eradicated, and it is still the only infectious disease to be totally wiped out. A feat which would not have been achieved if not for Onesimus.

He was amongst the best Bostonians of All Time by the Boston magazine in 2016.

Video credits: Black Gems Unearthed


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