Summary: This article tells the story of Onesimus, an African slave who introduced smallpox inoculation to the American colonies in the early 18th century. His knowledge, which he learned in his homeland of Komontse (modern-day Ghana), helped save many lives during a smallpox epidemic in Boston in 1721.


Great Men and History

There is a tendency to view history from the perspective of the so-called greats: the conquerors, generals, and politicians, those who often clumsily wielded influence and power. But the progress we have become so accustomed to in the modern world is often not the result of a wise politician; it is thanks to the innumerable people who helped create a better world each day by sharing knowledge with one another. A perfect example of this phenomenon is the story of Onesimus, an African slave responsible for introducing smallpox inoculation to the American colonies.

The Diary of Cotton Mather and Onesimus

We know little about Onesimus with certainty. Everything we do know about him originates in the diary of his master, Cotton Mather. Mather, a clergyman, was “gifted” Onesimus in 1706 by his congregation in Boston, Massachusetts. Mather named him Onesimus, a Greek word meaning useful and a reference to a slave Saint Paul met while imprisoned. A distasteful name, but also evidence that a person named Cotton, whose father and son were named Increase, should not be trusted to name anyone.

Mather remarks that Onesimus was from “Guaramantee.” Mather was likely attempting to spell Komontse, located in modern-day Ghana, suggesting that Onesimus may have been part of the Akan people, known for their elaborate jewelry and sculpture. In line with the Puritan beliefs of his time, Mather attempted to convert Onesimus to Christianity and taught him how to read and write, noting he was “a pretty intelligent fellow.” Onesimus was married, but Mather’s lack of familiarity with the bride implies she lived in a different household.

A Lethal Disease

In the 18th century, smallpox was one of the most lethal diseases on the planet. Scholars have estimated that each year 400,000 people died from smallpox. Thirty percent of people who contracted smallpox died, and those who survived were marked by terrible scars. Throughout western and sub-Saharan Africa, people figured out ways to combat smallpox through inoculation. This procedure involved rubbing smallpox scabs and fluid into small scratches on the patient’s skin and infecting the patient with a milder version of smallpox. After a few weeks of symptoms, the patient would become immune to smallpox.

In 1716, Mather recorded Onesimus describing the process of inoculation. Mather asked Onesimus if he had contracted smallpox before, and Onesimus answered “both Yes and No.” He explained that as a boy, he had “undergone an Operation, which had given him something of ye Smallpox, & would forever Praeserve him from it.” Onesimus described the procedure to Mather, who researched further and found that many cultures practiced inoculation, but not colonial Massachusetts.

The Epidemic of 1721

In 1721, a smallpox epidemic broke out in Boston, infecting half of the 11,000 residents. Mather, aware of inoculation thanks to Onesimus, promoted inoculation but was met with hostile responses. Many colonists, believing that slaves were plotting to overthrow their masters, distrusted medical advice from the slaves. The more religious Bostonians argued that the outbreak resulted from God’s divine will and that interfering was immoral. As a result, Mather was lampooned by his fellow colonists, with one being so disgruntled as to throw a bomb into Mather’s home.

Following Mather’s advice, a physician named Zabdiel Boylston inoculated his six-year-old son and two slaves. Of the 280 people inoculated in Boston, only 6 died. In stark contrast, of the 5,889 who were not inoculated, 844 died, a rate of 14 percent. The epidemic of 1721 was not the last time Boston would experience an outbreak of smallpox, but now, for the first time in the colony, there was a way to combat the dreaded disease thanks to the knowledge of Onesimus.

Smallpox and the Revolutionary War

Some historians have argued that without the introduction of inoculation, the colonists might not have won the Revolutionary War. Most deaths during the war were caused not by battle but by disease, especially smallpox. Future president John Adams wrote, “The smallpox is ten times more terrible than Britons, Canadians, and Indians together.” George Washington had similar thoughts to those of Adams, observing that smallpox was “more destructive than the sword.” To maintain the Continental Army’s manpower, Washington decided to have the army inoculated. In a letter to the medical director of the Continental Army, Dr. William Shippen Jr., Washington wrote: “Finding the smallpox to be spreading much and fearing that no precaution can prevent it from running thro’ the whole of our Army, I have determined that the Troops shall be inoculated.” Washington enacted the first medical mandate in American history, an unpopular policy at the time but a necessary measure that helped win the war.

Onesimus the Unsung Hero of Progress

The method of inoculation Onesimus described was eventually replaced with Edward Jenner’s development of vaccination in 1796. On May 8, 1980, the World Health Organization announced the eradication of smallpox, owing to the global spread of immunization, a momentous triumph of medicine.

The story of Onesimus is a fitting illustration of the economist F. A. Hayek’s view of progress in The Constitution of Liberty. He observed that we have a habit of “regarding economic progress chiefly as an accumulation of ever greater quantities of goods and equipment.” However, progress does not consist of having more of the same goods. Hayek explains that the rise “of our standard in life is due . . . to an increase in knowledge which enables us not merely to consume more of the same things but to use different things, and often things we did not know before.”

The history of politics tends to focus on the elites of society, the ones in a privileged position to hold political power. The history of progress is a much more egalitarian story of people like Onesimus, from all walks of life, contributing to increased knowledge, health, and comfort. The history of power is bleak, and the history of progress is hopeful.