Increasingly, historians are blaming diseases imported
from the Old World for the staggering disparity between
the indigenous population of America in 1492—new esti-
mates of which soar as high as 100 million, or approxi-
(5) mately one-sixth of the human race at that time—and
the few million full-blooded Native Americans alive at
the end of the nineteenth century. There is no doubt that
chronic disease was an important factor in the precipi-
tous decline, and it is highly probable that the greatest
(10) killer was epidemic disease, especially as manifested in
virgin-soil epidemics.
Virgin-soil epidemics are those in which the popula-
tions at risk have had no previous contact with the
diseases that strike them and are therefore immunologi-
(15) cally almost defenseless. That virgin-soil epidemics were
important in American history is strongly indicated by
evidence that a number of dangerous maladies—small-
pox, measles, malaria, yellow fever, and undoubtedly
several more—were unknown in the pre-Columbian
(20) New World. The effects of their sudden introduction
are demonstrated in the early chronicles of America,
which contain reports of horrendous epidemics and steep
population declines, confirmed in many cases by recent
quantitative analyses of Spanish tribute records and
(25) other sources. The evidence provided by the documents
of British and French colonies is not as definitive
because the conquerors of those areas did not establish
permanent settlements and begin to keep continuous
records until the seventeenth century, by which time the
(30) worst epidemics had probably already taken place.
Furthermore, the British tended to drive the native
populations away, rather than enslaving them as the
Spaniards did, so that the epidemics of British America
occurred beyond the range of colonists’ direct
(35) observation.
Even so, the surviving records of North America do
contain references to deadly epidemics among the indige-
nous population. In 1616-1619 an epidemic, possibly of
bubonic or pneumonic plague, swept coastal New
(40) England, killing as many as nine out of ten. During the
1630’s smallpox, the disease most fatal to the Native
American people, eliminated half the population of the
Huron and Iroquois confederations. In the 1820’s fever
devastated the people of the Columbia River area,
(45) killing eight out of ten of them.
Unfortunately, the documentation of these and other
epidemics is slight and frequently unreliable, and it is
ecessary to supplement what little we do know with
evidence from recent epidemics among Native Ameri-
(50) cans. For example, in 1952 an outbreak of measles
among the Native American inhabitants of Ungava Bay.
Quebec, affected 99 percent of the population and killed
7 percent, even though some had the benefit of modern
medicine. Cases such as this demonstrate that even
(55) diseases that are not normally fatal can have devastating
consequences when they strike an immunologically
defenseless community.