Onesimus was an enslaved West African man whose African teachings helped to reduce the impact of the smallpox outbreak in Boston, Massachusetts.
Little is known about Onesimus before he was enslaved other than he was Coromantee (also known as Akan people from modern Ghana). Like many enslaved people his original name, age and date of birth have been lost due to the barbarism of slavery. The first documented evidence is of him being brought to America as a slave in 1706.
In December 1706, Puritan minister Cotton Mather was gifted a slave by his congregation. Mather named this slave Onesimus, after an enslaved man in the Bible whose name meant “useful.” He believed that owners of enslaved people had a duty to convert enslaved people to Christianity and educate them. Mather saw Onesimus as highly intelligent and taught him to read and write.
In the early 1700s, smallpox was ripping through New England and other American Colonies. In Massachusetts, smallpox arrived with cargo ships to Boston. The authorities couldn’t do much beyond imposing quarantines and treating the sick.
Smallpox patients experienced fever, fatigue and a crusty rash that could leave disfiguring scars. In up to 30 percent of cases, it killed.
In 1716, Onesimus told Mather that he once had smallpox and was cured having undergone an operation that was regularly performed by his people in Africa. He described a process of variolation which consisted of taking the pus from the blisters of smallpox patients and rubbing it into a cut in a healthy person.
Variolation wasn’t a vaccination, which involves exposure to a less dangerous virus to provoke immunity. But it did activate the recipient’s immune response and protected against the disease most of the time.
After hearing Onesimus’ story, Cotton Mather began to research the practice of variolation. He spoke to other enslaved Africans and found that it was practiced in many parts of the world, not just Africa.
Places like China and Turkey had their own versions of variolation based on the same principle of exposing a person under controlled circumstances rather allowing them to contract it naturally. The practice was so effective in providing immunity that African slaves sold in Massachusetts at the time were deemed to be more valuable if they had a variolation scar.
Ridiculed and vindicated
Mather became a convert and spread the word across Massachusetts with the hope that smallpox could be prevented. However, Mather’s fellow white Bostonians were not as enthusiastic as he was. At the beginning of the eighteenth century, public opinion in New England held that Africans lacked the “Enlightenment gifts of rationality and reason”. They derided this method because they were suspicious of African medicine and of Onesimus’ motives.
Despite playing a prominent role in the Salem witch trials of 1692, Mather now found himself ridiculed. Someone even threw an explosive devise though his window with an angry note attached.
However, Mather did have one ally. Zabdiel Boylston was the only physician in Boston who supported the technique and in 1721 he got his chance to put this early form of inoculation to the test. That year, a smallpox epidemic spread from a ship to the population of Boston, infecting about half of the city’s residents.
Boylston inoculated his own son and the slaves in his possession. Then he began inoculating other Bostonians. The result was that of the 242 people he inoculated, only six died—one in 40, as opposed to one in seven deaths among the population of Boston who didn’t undergo the procedure.
At the end of the epidemic, 14 per cent of the population of Boston was dead. Based on this experiment, the practice of variolation became more accepted in the colonies facing smallpox epidemics.
Onesimus’ personal life
Whilst serving the Mather family, Onesimus married and had two children both of whom died before they were ten years old. His son, Onesimulus, died in 1714. His second child, Katy, died due to consumption.
After the deaths of his children Onesimus found himself continually rejecting Cotton Mather’s attempts to convert him to Christianity. Mather saw his inability to convert his slave as his failure as a Puritan evangelist and head of his household, as Onesimus’ refusal was supposed to bring God’s displeasure on the Mather family.
Onesimus’ refusal to convert led to Mather’s unhappiness with his presence in the household. Mather’s diary reports “stubborn behaviour” from Onesimus following the death of his children.
In 1716, Onesimus attempted to buy his freedom from Mather, raising funds to purchase his freedom. Mather agreed but placed conditions on his release requiring that he remain available to perform work in the Mather household at their command. It’s possible that Mather’s failure to convert Onesimus helped him decide to let him go.
We know about Onesimus because Cotton Mather was a prolific author. Not only did he keep a diary but following the Boston epidemic, he published a medical treatise The Angel of Bethesda where he recounted the method of inoculation and spoke of his research and conversations with the enslaved people. We don’t know if Onesimus realised what a huge impact his knowledge had in saving so many lives or what happened once he was freed.