The Footprint Made by Smallpox


Transportation and migration has been important to Homo sapiens since the time of the hunter-gatherer. Humans have used the different methods of transportation since this time for a number of reasons (i.e. survival in the case of the hunter-gatherer, to spread religion, or in order to search for precious minerals and spices). What few of these human travelers failed to realize is that often diseases were migrating with them. This essay will look at the spread of the disease smallpox. In the following I hope to reveal the history of smallpox as well as why it devastated the New World.

In order to understand the history of smallpox one first has to understand how diseases like it evolve. Much like other species, diseases that survive in the long run are the microbes that most effectively reproduce and are able to find suitable places to live. For a microbe to effectively reproduce, it must "be defined mathematically as the number of new infected per each original patient." This number will largely depend on how long each victim is able to spread the virus to other victims.(Diamond, 198)

Besides reproduction, a microbe needs a suitable environment to survive. In most cases this environment is a large animal population. With this type of environment a microbe is able to survive by, ironically, not killing everyone off. If a population is small and dense, the microbe will spread to all the animals in the immediate area and, if lethal, kill the entire species off. This not only ends the existence of the animal in this immediate population, but the existence of the microbe since it has no carrier to leach itself to. Therefore, the ideal population for a deadly microbe is a population that is large, but is also not too dense. This environment provides a virus with many carriers but also allows the microbe to move around to different regions of the population without infecting everyone at once. (Diamond, 198)

Smallpox is a disease that is believed to have originated around 1500 B.C. in ancient Egypt. By 430 B.C. it appears that it reached Athens via trade ships according to records kept by the Athenian historian Thucydides. "The Plague of Athens", the name the Greeks had for the disease, spread to the Roman Empire by 150 A.D. by way of the returning army from Greece. From this point on, smallpox moved throughout the European and North African regions in various ways.(Thomson, 118) Mark Thomson, author of "The Migration of Smallpox and its Incredible Footprint on Latin America", explains:

Religious movements helped spread the disease. Islamic armies are believed to have brought smallpox from north Africa to Spain, Portugal and France. During the twelfth and thirteenth centuries, the religious crusades to western Asia helped to reintroduce and further spread smallpox in Europe. Smallpox also accompanied armies bent on conquest, merchants following trade routs and expanding populations. By the fourteenth century, smallpox was well-established in Germany, Spain, Italy and France. (Thomson, 118)

Ultimately, smallpox would reach the New World. A large carrier of the disease to the New World was not the Europeans in search of new lands, rather, the slaves the Europeans carried over in the cramped quarters of a ship where the disease could spread rapidly.

Once smallpox came in contact with the New World it decimated populations. As many as 2 million people died on the island of Hispaniola in the four following years after contact had been made with Columbus. In some cases, small populations like on the island of Taino (26,000 people in 1514 A.D.) were extinct within a short period of time (1542 A.D.) So why was smallpox so lethal in the New World than in Europe? "In Europe, the disease was endemic. As a result, many adults were exposed to smallpox as children, and those that survived had immunity."(Thomson, 119 -120) In a sense, the Europeans had already been through a form of natural selection. The natives of the New World had no previous contact with this disease and therefore had no natural defense against it.

Some of the devastation in the New World was happenstance also. Ironically, the technology that made the Aztecs of South America so great, lead to their demise. The Aztecs had a large trade route throughout their empire; unfortunately, it also provided smallpox a highway to the entire population.(Thomson, 121)

Smallpox has obviously left a large footprint in our history. Aside from devastating populations in Europe, and in particular the New World, the disease can be accounted for a large change in political, religious, and economic change. In South America, this disease killed many of the elders and tribal leaders. This threw both the religious and political aspects of this society into chaos. Smallpox also hit the labor supply in South America hard. After the native laborers were infected with the disease, the Spanish had to rely on imported slaves to carry out the mining and agricultural work. Thomson states that for this reason, "black replaced Indians as a major population element of the Western Hemisphere. Today, for example, Jamaica, the Bahamas, Haiti, Cuba, and Puerto Rico all have substantial or predominantly black populations in place of indigenous Indians lost to smallpox." (Thomson, 122) This, in turn, lead to the triangle slave trade, which produced the largest level and wide spread practice of slavery ever seen. Many historians agree that these turn of events could not have happened without smallpox. This single microbe not only changed the population makeup of the New World, but forever changed the New World culture and economy.


1) Diamond, Jared, "Ch. 11: Lethal gift of livestock," in "Guns, Germs, and Steel" W.W. Norton & Co, 1997, ISBN 0-393-03891-2, pp. 195-214

2) Thomson, Mark. "Junior Division Winner: The Migration of Smallpox and Its Indelible Footprint on Latin American History". The History Teacher. 1998.


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last updated 2/6/03