The New World Isolation

Before Christopher Columbus [Cristóbal Colón in Spanish] arrived in the Western Hemisphere in 1492, the indigenous people of the Americas (The New World) did not suffer from any of the diseases which had plagued the rest of mankind for so long. For at least 15,000 years, the people of the Americas – for the most part – had been isolated from the entire Old World (which included Europe, Asia and Africa). This meant that many diseases which had regularly plagued the Old World were never experienced by the Native American populations.

According to Donald R. Hopkins, in Princes and Peasants (1983), “the native populations of North and South America were blissfully unaware of smallpox’s existence when Christopher Columbus re-established contact between the Old and New Worlds in 1492. Smallpox made its first appearance in the New World only fifteen years later.”[1]  The native people of the Americas were especially vulnerable to smallpox because they’d never been exposed to the virus and thus possessed no natural immunity.

An Aged-Old Curse: Smallpox

Smallpox was a truly terrible disease. It was caused by an inhaled virus, which caused fever, vomiting and a rash, eventually covering the body with fluid-filled blisters. These blisters turned into scabs which usually left terrible scars on the victims. On average, three out of every ten people who got smallpox died from it. But, in early Sixteenth Century Mexico, the fatality rate was even higher because no one had any immunity to the disease. Another third of those afflicted with smallpox usually became blind.[2]

Smallpox Becomes Endemic to the Old World

It is believed that smallpox may have existed as early as 1500 B.C. and visited such places as China, Egypt and India. Most historians believe that smallpox was probably introduced into Europe during the 11th Century’s Crusades. For several hundred years, all of Europe was experiencing periodic and devastating smallpox epidemics. But, over time, smallpox became endemic to most “Old World” populations.[3]  According to Dictionary.com, endemic in relation to a disease means “persisting in a population or region, generally having settled to a relatively constant rate of occurrence.”

According to Jonathan B. Tucker, “Somewhat paradoxically, the longer a society lived with smallpox, the less severe its demographic impact became. In densely populated urban areas, the disease smoldered continuously at a low level and the intervals between major outbreaks were fairly short. As a result, nearly everyone who survived into adulthood was immune and the victims were mainly small children.”[4] However, none of the New World people had developed immunity to those diseases and, as a result, they represented fertile breeding grounds for some of the most virulent diseases ever known to man. When Europeans began to explore and colonize other parts of the world, smallpox traveled with them. The epidemiologist Mark Thompson wrote, “Whatever its origins, smallpox soon spread, probably carried by armies seeking new conquests and merchants engaged in trade.”[5] 

How Could Smallpox Cross the Atlantic?

By the Sixteenth Century, most adult Europeans and many of their African slaves had probably had smallpox. As a result, they were partially or totally immune to the disease. But how could a voyage of several weeks from Spain to the Caribbean carry that dangerous disease across the Atlantic? Given the length of the trans-Atlantic voyage, a Spanish sailor aboard a ship who contracted smallpox before his embarkation would probably die before he arrived at his destination on the western end of the Atlantic.  In addition, the strong sunlight experienced on the tropical sea voyage was not conducive to the survival of the smallpox virus. For this reason, it took fifteen years after Columbus’ first voyage before smallpox gained a foothold in the Americas.[6] As one historian has noted, smallpox "is a deadly malady, but it lasts only a short time in each patient."[7] There is also no non-human carrier of smallpox; it must be transmitted from person to person.

Spread easily through the air, roughly twelve days pass between acquiring the germ and developing the initial symptoms, which are “deceptively benign.” Thea Baldrick, a contributing science writer with a B.S. in Biology, in her 2024 article about smallpox in the Americas, notes that “the first stage of the disease mimics the flu as the body tries to fight off the initial invasion. In the second stage, the temperature falls to almost normal. The microbe journeys through the lymph system, replacing cells in the liver and spleen by commandeering the human DNA and adapting it to its own use. Finally, the virus leaks out or bursts from the cells, enters the bloodstream, and appears on the skin as a rash.”[8]

The 1492 Landing of Christopher Columbus

Thea Baldrick noted that in 1492 Christopher Columbus landed on “a still unidentified island,” that he named San Salvador. She points out that “its exact location today remains a matter of debate,” but “its shadowy identity makes it a fit introduction for looking back at the peoples inhabiting” the so-called “New World.” She further notes that “many of their cultures disappeared into the mists from the intentional destruction of their conquerors and the ravages of disease, most notably smallpox.”[9]

The Spaniards Occupy the Caribbean (1493)

In 1493, Columbus brought 1,300 men to colonize Hispaniola [today, the Dominican Republic and Haiti] with the intention of establishing a permanent settlement. However, the native people and hurricanes impeded their early progress. Eventually, the settlements were successful, and Hispaniola, Cuba, Puerto Rico and other Caribbean islands were settled by the Spaniards. To operate their newly developed mines and plantations, the conquerors employed the native people, subjecting them to very brutal working conditions. According to the author Jonathan B. Tucker, “The resulting high death rates depleted the indigenous labor pool, leading the Spanish to import slaves from West Africa as replacements. Since many African slaves came from regions where smallpox was endemic, the slave trade introduced the disease to the Americas.”[10]

A current map of Caribbean Islands and the surrounding areas are shown below:[11]

Smallpox Arrives in the Caribbean (1507)

By 1503, the Spaniard were importing large numbers of enslaved Africans to work in the farms and mines of their new settlements. Then, in 1507, the first smallpox epidemic struck, wiping out whole tribes on Hispaniola.[12] The epidemic eventually subsided, but the native labor pool had shrunk considerably. Thus, the Spaniards brought more and more enslaved people in to replace the native workers, and each ship carried the risk of another epidemic. And the slave population soon exceeded the population of Spanish colonists.[13]

Smallpox Strikes the Caribbean Again (1518-1519)

In December 1518, smallpox appeared again, initially among the enslaved Africans in the mines of Hispaniola. By May 1519, one-third of the remaining native people on Hispaniola died of smallpox, but the disease did not remain isolated on the island. It spread to Cuba and then Puerto Rico, killing half the indigenous populations on those islands as well.[14] However, soon smallpox would be carried to the North American Continent, and it would wreak even worse havoc with the Indigenous people there.

Hernán Cortés Arrives in Mexico (April 1519)

On April 22, 1519, a fleet of eleven Spanish galleons, which had been sailing northward along the eastern Gulf Coast of Mexico, dropped anchor in what is now Veracruz State. Under the command of the Spanish adventurer Hernán Cortés, these vessels bore 450 soldiers, 100 sailors, and 16 horses. After establishing relationships with the local natives, he established La Villa Rica de la Vera Cruz (The Rich Town of the True Cross), what today is known as the Port of Veracruz.  His ultimate goal was to work his way westward into the interior of the continent to meet with Moctezuma, Emperor of the massive Aztec Empire in his capital city, Tenochtitlán.

Cortés Arrives in Tenochtitlán

Cortés met with and forged alliances with many of the indigenous people as he moved west. He had left the Gulf Coast on August 8, 1519 with a force of Spaniards, Cuban Indian servants, and allied Indigenous forces. In November, they arrived in the Aztec capital, Tenochtitlán. Along the way, they were forced to wage war against some of the indigenous tribes, while other natives joined the Spaniards. Cortés finally met with Emperor Moctezuma, but the Aztecs leaders became suspicious about Cortés’ intentions. Eventually Moctezuma was killed by his own subjects and the caciques of Tenochtitlán chose Cuauhtémoc, a nephew of Moctezuma and a brilliant military leader who fiercely believed that his Aztec army could defeat the invaders. 

The Flight of Cortés

Eventually, Cortés’ machinations led to a confrontation in which he and his forces were put under siege within the capital itself. On the night of June 30/July 1, the Aztecs fell upon the armies of Cortés and his allies and inflicted heavy damage on them. This night is known as La Noche Triste, or “the Night of Sadness,” and many soldiers drowned in Lake Texcoco when the vessel carrying them sank. Cortés and his forces fled the capital, suffering incredible losses. 

With the Aztecs in hot pursuit, Cortés’ army fled to Tlaxcala to obtain reinforcements. On July 8, 1520, the army came upon a legion of nearly 200,000 Aztecs sent by Cuauhtémoc, Moctezuma's successor. There, at the Battle of Otumba, the Spaniards managed a smashing victory that dissuaded the Aztecs from pursuing the Spaniards and their allies any farther. As the exhausted army approached Tlaxcala, they were greeted by their Indian allies and given refuge. 

The Expedition of Narvaez

Earlier, Diego Velázquez de Cuéllar, the Governor of Cuba, who had originally sent Cortés to Mexico, became jealous and suspicious of his successes and sent another expedition, led by Pánfilo de Narvaez, to Mexico. Narvaez left Cuba in early March and landed at Cempoala, near present-day Vera Cruz, on April 23, 1520.[15] Cortes left a contingent in Tenochtitlan and went to stop the incoming ships from arresting him.  He, his men, and his native allies took Narvaez by surprise, overcame them, and then quickly returned to Tenochtitlan.[16]

According to several sources, including D’Ardois (1961) and Smith (1974), it was an enslaved African slave in Narvaez’s entourage, Francisco de Baguia, who first introduced smallpox to the American mainland.[17] From May to September I520, smallpox spread slowly inland , reaching Tenochtitlan in September or October.[18]

The Spaniards Seek Refuge in Tlaxcala (July 1520)

“While the Spaniards rested and recuperated” in Tlaxcala, wrote Richard Lee Marks, “it occurred to Cortés and his men to wonder why the great armies from Tenochtitlán were not pursuing them.”  The Aztecs had not attacked or laid siege to Tlaxcala, giving the Spaniards and Tlaxcalans precious time to heal and recover from their catastrophic defeat on “La Noche Triste.” Later, Cortés would learn that an epidemic of smallpox was devastating Tenochtitlán.[19] Years later, Francisco de Aguilar, once a follower of Cortes and later a Dominican friar, recalled the terrible retreat of the Noche Triste. “When the Christians were exhausted from war,” he wrote, “God saw fit to send the Indians smallpox, and there was a great pestilence in the city.”[20]

Smallpox in the Aztec Capital

As stated earlier, the smallpox epidemic broke out in Tenochtitlán around September 1520. The epidemic lasted for at least seventy days and struck people in every corner of the city, immobilizing much of the population. Many of the afflicted could not walk or move. While many died from the plague itself, some died from hunger. Individuals who were sick with smallpox could not get out to procure or prepare food. They were also too sick to care for their other family members, so some native people starved to death in their beds. Some people came down with a milder form of the disease and would eventually recover. However, their looks were ravaged, for wherever a sore broke out, it gouged an ugly pockmark in the skin. And a large number of survivors lost their sight.

A Spanish friar, Fray Toribio Motolinía, described the epidemic that resulted in his History of the Indians of New Spain, which he completed in 1541.[21] Motolinía stated that smallpox was “a disease which had never been seen here… when the smallpox began to attack the Indians it became so great a pestilence among them throughout the land that in most provinces more than half the population died.” Motolinía also noted that “the Indians did not know the remedy for the disease and were very much in the habit of bathing frequently, whether well or ill, and continued to do so even when suffering from smallpox.” As a result, “they died in heaps, like bedbugs. Many others died of starvation because, as they were all taken sick at once, they could not care for each other, nor was there anyone to give them bread or anything else.”[22]

 “In many places it happened that everyone in a house died, and as it was impossible to bury the great number of dead, they pulled down the houses over them in order to check the stench that rose from the dead bodies," Fray Toribio Motolinía wrote. In Tenochtitlán, the dead were cast into the water, "and there was a great, foul odor; the smell issued forth from the dead."[23]

The Final Battle (1521)

The length of the epidemic provided Cortés and his troops a desperately needed respite to reorganize and prepare a counterattack. Had there been no epidemic, the Aztecs, their war-making potential unimpaired and their warriors fired up with a feeling of victory, could have pursued the Spaniards and defeated them. But the epidemic sapped the endurance of Tenochtitlan to survive the Spanish assault.

Hernán Cortés’ army left Tlaxcala on December 26, 1520 on its march to the Aztec capital. With a rebuilt army of 600 Spanish soldiers and between 110,000 and 150,000 Mexican warriors, Cortés intended to occupy the city of Texcoco and blockade Tenochtitlán from there. In May 1521, the Spanish army returned with its indigenous allies to Tenochtitlán and was able to capture the Aztec capital after three months. Finally, on August 13, 1521, after several decisive battles and an almost eighty-day siege, Tenochtitlán surrendered, and the Spaniards announced their victory over the Aztec Empire.

When the city fell "the streets, squares, houses, and courts were filled with bodies, so that it was almost impossible to pass. Even Cortes was sick from the stench in his nostrils."[24] Many of Cortés’ men had had smallpox as children in Spain, so most of the Spanish soldiers had immunity.  In fact, Hopkins noted that “this differential immunity enhanced the awe in which they were held by the demoralized Indians.”[25]

The Aztec Empire: A Conduit for the Spread of Smallpox

By 1519, the Aztec Empire was a multi-ethnic, multi-lingual realm stretching  more than 80,000 square miles throughout central and southern Mexico. Fifteen million people lived in 489 communities within 38 provinces and paid tribute to the Emperor Moctezuma II. When smallpox arrived in Mexico, the Aztec Empire proved to be a conduit for the spread of smallpox to communities both north and south of the vast empire. The following map shows the breadth of the Aztec Empire [also known as the Triple Alliance of Tenochtitlán, Tlacopan, and Texcoco], as well as its neighbors, the Mayans (to the southeast) and the Purépecha Empire (to the northwest).[26]

Population Decline in Central Mexico

According to Magner (1942), by the time the epidemic ended after a few months, an estimated 2 to 3.5 million Mexican Indians had died.[27] And Crosby (1967) states that Central Mexico’s population declined from about 25 million before the conquest to about 16.8 million ten years later (from all causes).[28]

The Epidemic Spreads Beyond the Valley of Mexico

The smallpox epidemic had travelled westward from the Gulf Coast to the center of the Aztec Empire, but over time, other native groups outside of the Valley of Mexico [the heart of the Aztec Empire] would be affected. When smallpox hit these communities, it affected everyone, including – as Crosby noted – “power structures.” Leaders died and the processes by which they were normally replaced” were disrupted. As an example, when Moctezuma died, his nephew, Cuauhtémoc, was elected the Lord of the Mexica. He directed the attacks on the Spaniards during the disastrous retreat from Tenochtitlan. But suddenly Cuauhtémoc died of smallpox. Probably many others wielding decisive power in the ranks of the Aztecs and their allies died in the same period, breaking dozens of links in the chain of command.[29]

The German anthropologist Hanns J. Prem has noted that, “because smallpox spread quickly to other regions at that time neither conquered nor even known about, information regarding the area affected by the epidemic must be incomplete.” It is believed that the smallpox epidemic spread to the Andean region in South America between 1524-1526, where “it caused great population decline, killing the Inca ruler and his heirs and precipitating social upheaval well before the arrival of Pizarro [1531].”[30]

The Epidemic Reaches Mayan Territory (1520-1521)

Two years after the fall of Tenochtitlán, when Cortés’ lieutenant Pedro de Alvarado invaded Mayan territory, a small wave of smallpox had already preceded him, arriving in their land in 1518 or 1519 thanks to trade expeditions from Hispaniola. Then, a second epidemic raged through the Mayan kingdoms from 1520 to 1521. By the time Alvarado entered the area now known as Guatemala Highlands, smallpox had already killed half the Kaqchikel population, including two leaders. The Mayans called the disease nohkakil, the “Great Fire.”[31]

Modern knowledge of the impact of these diseases on populations with no prior exposure suggests that 33–50% of the population of the highlands perished. Population levels in the Guatemalan Highlands did not recover to their pre-conquest levels until the middle of the 20th century.[32]

Old World Diseases Precede the Spaniards

Daniel Reff pointed out, “The smallpox pandemic of 1518-25 is one of the earliest and better known disease episodes that had a profound impact on native Americans. Wherever Europeans went, from New England to the Amazon and from Alaska to Tierra del Fuego, Old World diseases accompanied and, some believe, preceded the invaders. Because native Americans had not been exposed previously to maladies such as malaria, influenza, and smallpox, they lacked genetic traits that promoted resistance to these diseases.”[33]

Vulnerability Subsides Over Time

According to William H. McNeill, the vulnerability of a human population to new infections usually subsides after 120 to 150 years of exposure.[34] By 1640, a larger percentage of Indians were able to survive bouts of smallpox and measles in childhood and, as a result, were immune when new epidemics struck. Although these diseases continued to take a great toll on the young, “their reduced severity among those of reproductive age lessened their long-term demographic impact.” [35]

The indigenous population of the Valley of Mexico had dropped from 1.5 million Indians in 1519 to some 70,000 Indians by the mid-seventeenth century. However, after that the Indian population increased to 120,000 in 1742 and 275,000 in 1800.[36] But epidemics continued to hit the Valley of Mexico at regular intervals: in 1727-28, 1736-41, and 1778-80.[37]

The Conquest Simplified

Mexico's native population was one of the first in the Americas to experience a smallpox epidemic in which many people succumbed to the disease. In 1520, the first wave of smallpox in Mexico killed an estimated five to eight million people. But the worst was still yet to come. From 1545 to 1576, up to 17 million people may have died from smallpox and other diseases. Many of the deaths in the second wave are thought to be the result of hemorrhagic fevers.[38]

When the Spaniards conquered Mexico and subdued the Aztec Empire, they had a formidable ally: smallpox.  One can only guess what might have happened if smallpox had not weakened the Indigenous population in the way that it did. But the epidemics and illnesses continued for the next two centuries: measles, typhus, mumps, pneumonic plague, influenza, and more smallpox. The nightmare was not over. The following map shows a simplified version of the journey of the smallpox epidemics in the Americas.

Bibliography

Acuna-Soto, Rodolfo; Stahle, David W.; Cleaveland, Malcolm K.; Therrell, Matthew D. “Megadrought and Megadeath in 16th Century Mexico,” Emerging Infectious Diseases, (April 2002) 8 (4): 360–362.

Baldrick, Thea. “Smallpox in the New World: History, Victims, & Symptoms,” The Collector (May 7, 2024). Online: https://www.thecollector.com/smallpox-effect-new-world/ [Accessed 8/24/2024].

Crosby, Alfred W., “Conquistador y Pestilencia: The First New World Pandemic and the Fall of the Great Indian Empires,” The Hispanic American Historical Review, Aug., 1967, Vol. 47, No. 3 (Aug., 1967), pp. 321-337.

D’Ardois, G.S., “La Viruela en la Nueva España,” Gac. Med. Mex. 91 (1961): 1015-1024.

Do Amaral, Carlos, “Historia de Variola,” A. Medicina Contemporanea, 78 (1960): 537-571.

De las Casas, Bartolome. Historia de las Indias. Madrid, 1957.

Diaz del Castillo, Bernal.  The Bernal Diaz Chronicles: The True Story of the Conquest of Mexico. Garden City, N.Y., 1956.

Duran, Diego. The Aztecs. The History of the Indies of New Spain. New York, 1964.

Foster, Elizabeth A. Motolina’s History of the Indians of New Spain. Berkeley: Cortes Society, 1950.

Hirsch, A. Handbook of Geographical and Historical Pathology. Vol. 1. London: New Sydenham Society. 1883.

Hopkins, Donald R. Princes and Peasants. Chicago: University of Chicago Press, 1983.

Knight, Alan. Mexico: Volume 2: The Colonial Era. Cambridge: Cambridge University Press, 2002.

Lovell, W. George. Conquest and Survival in Colonial Guatemala: A Historical Geography of the Cuchumatán Highlands, 1500–1821 (3rd ed.). Montreal, Canada: McGill-Queen's University Press, 2005.

Marks, Richard Lee. Cortés: The Great Adventurer and the Fate of Aztec Mexico. New York: Alfred A. Knopf, 1994.

Martin, Cheryl English. Rural Society in Colonial Morelos. University of New Mexico Press, Albuquerque, 1985.

McCaa, Robert. “Spanish and Nahuatl Views on Smallpox and Demographic Catastrophe in Mexico,” The Journal of Interdisciplinary History, Vol. 25, No. 3 (Winter, 1995), pp. 397-431

McNeill, William H. Plagues and Peoples. New York: Anchor Books, 1976.

Prem, Hanns J. “Disease Outbreaks in Central Mexico during the Sixteenth Century,” In The Secret Judgments of God: Native Peoples and Old World Disease in Colonial Spanish America, ed. Noble David Cook and W. George Lovell, pp. 22-50. Norman: University of Oklahoma Press, 1992.

Reff, Daniel T. Disease, Depopulation and Culture Change in Northwestern New Spain, 1518-1764. Salt Lake City: University of Utah Press, 1991.

Sahaguin, Bernardino de. General History of the Things of New Spain. Santa Fe, 1950-59.

Smith, Michael M., “The ‘Real Expedición Marítima de la Vacuna’ in New Spain and Guatemala,” Trans. Amer. Phil. Soc., 64 (1974), part 1: 1-74.

Thompson, Mark. “The Migration of Smallpox and Its Indelible Footprint on Latin American History,” The History Teacher, Vol. 32, No. 1 (Nov., 1998), pp. 117-131.

Tucker, Jonathan B. Scourge: The Once and Future Threat of Smallpox. New York: Atlantic Monthly Press, 2001.

Zvi Dor-Ner, Columbus and the Age of Discovery. New York: William Morrow and Company, Inc., 1991.

Footnotes

[1] Donald R. Hopkins, Princes and Peasants (Chicago: University of Chicago Press, 1983), p. 204.

[2] Center for Disease Control, “History of Smallpox” (Feb. 2021). Online: https://www.cdc.gov/smallpox/history/history.html [Accessed 8/8/2024].

[3] Center for Disease Control, “History of Smallpox.”

[4] Jonathan B. Tucker, Scourge: The Once and Future Threat of Smallpox (New York: Atlantic Monthly Press, 2001), p. 8.

[5] Mark Thompson, “The Migration of Smallpox and Its Indelible Footprint on Latin American History,” The History Teacher, Vol. 32, No. 1 (Nov., 1998), p. 118.

[6] A.W. Crosby, “Conquistador y Pestilencia: The First New World Pandemic and the Fall of the Great Indian Empires,” Hispanic American Historical Review (1967) 47: 326-327; Mark Thompson, op. cit. Footnote 20, p 124.

[7] Crosby, op. cit. p. 326.

[8] Thea Baldrick, “Smallpox in the New World: History, Victims, & Symptoms,” The Collector (May 7, 2024). Online: https://www.thecollector.com/smallpox-effect-new-world/ [Accessed 8/24/2024].

[9] Ibid.

[10] Jonathan B. Tucker, op. cit., p. 9.

[11] Kmusser, “Map of the Caribbean Sea and its Islands” (April 9, 2011). Online:

https://commons.wikimedia.org/wiki/File:Caribbean_general_map.png [Accessed 8/28/2024].

[12] Carlos Do Amaral, “Historia de Variola,” A. Medicina Contemporanea, 78 (1960); A. Hirsch, Handbook of Geographical and Historical Pathology. Vol. 1. London: New Sydenham Society. 1883; Donald R. Hopkins, op. cit., p. 204.

[13] Thea Baldrick, “Smallpox in the New World: History, Victims, & Symptoms,” The Collector (May 7, 2024). Online: https://www.thecollector.com/smallpox-effect-new-world/ [Accessed 8/24/2024].

[14] Ibid.; Donald R. Hopkins, op. cit., p. 205.

[15] Ibid.

[16] Thea Baldrick, op. cit.

[17] Michael M. Smith, “The ‘Real Expedición Marítima de la Vacuna’ in New Spain and Guatemala,” Trans. Amer. Phil. Soc., 64 (1974), part 1: 1-74; Donald R. Hopkins, op. cit., p. 205; G.S. D’Ardois, “La Viruela en la Nueva España,” Gac. Med. Mex. 91 (1961): 1015-1024; Elizabeth A. Foster, Motolina’s History of the Indians of New Spain (Berkeley: Cortes Society, 1950), p. 38.

[18] Robert McCaa, “Spanish and Nahuatl Views on Smallpox and Demographic Catastrophe in Mexico,” The Journal of Interdisciplinary History, Vol. 25, No. 3 (Winter, 1995), pp. 397-431; Hanns J. Prem, “Disease Outbreaks in Central Mexico during the Sixteenth Century,” In The Secret Judgments of God: Native Peoples and Old World Disease in Colonial Spanish America, ed. Noble David Cook and W. George Lovell, (Norman: University of Oklahoma Press, 1992), p. 26.

[19] Richard Lee Marks, Cortés: The Great Adventurer and the Fate of Aztec Mexico (New York: Alfred A. Knopf, 1994), p. 190.

[20] A.W. Crosby, op. cit., pp. 328-329; Bernal Diaz del Castillo, The Bernal Diaz Chronicles: The True Story of the Conquest of Mexico (Garden City, N.Y., 1956), p. 250; Diego Duran, The Aztecs. The History of the Indies of New Spain (New York, 1964), 323; Elizabeth A. Foster, Motolina’s History of the Indians of New Spain (Berkeley: Cortes Society, 1950), 38; Bernardino de Sahaguin, General History of the Things of New Spain (Santa Fe, 1950-59).

[21] Elizabeth A. Foster, op. cit.

[22] Ibid. p. 38.

[23] Ibid.; Foster, 1950, p. 38.

[24] A.W. Crosby, op. cit., pp. 329-330.

[25] Hopkins, op. cit., p. 207.

[26] Giggette, “Territorial Organization of the Aztec Empire 1519” (Nov. 4, 1519). Online: https://en.wikipedia.org/wiki/Aztec_Empire#/media/File:Territorial_Organization_of_the_Aztec_Empire_1519.png [Accessed 8/29/2024].

[27] J.A. Magner, Men of Mexico. Milwaukee: Bruce Publishing Co., 1942.

[28] Hopkins, op. cit., p. 207.

[29] A.W. Crosby, op. cit., p. 334.

[30] Hanns J. Prem, op. cit. p. 26.

[31] Hopkins, op. cit., p. 208; Thea Baldrick, op. cit.; W. George Lovell, Conquest and Survival in Colonial Guatemala: A Historical Geography of the Cuchumatán Highlands, 1500–1821 (Montreal, Canada: McGill-Queen's University Press, 2005: 3rd Edition), p. 70.

[32] Ibid.

[33] Daniel T. Reff, Disease, Depopulation and Culture Change in Northwestern New Spain, 1518-1764 (Salt Lake City: University of Utah Press, 1991), p. 1.

[34] William H. McNeill, Plagues and Peoples (New York: Anchor Books, 1976), p. 58.

[35] Cheryl English Martin, Rural Society in Colonial Morelos (University of New Mexico Press, Albuquerque, 1985), p. 56.

[36] Knight, Alan, Mexico: Volume 2: The Colonial Era (Cambridge: Cambridge University Press, 2002), pp, 20, 206.

[37] Ibid., p. 206.

[38] Acuna-Soto, Rodolfo; Stahle, David W.; Cleaveland, Malcolm K.; Therrell, Matthew D. (April 2002). "Megadrought and Megadeath in 16th Century Mexico," Emerging Infectious Diseases. 8 (4): 360–362.