184 
Frank Carney 
Types of over-population. There are two kinds of over-popu- 
lation, local and general. Some particular parts of a state may 
have too many citizens, whereas the state itself has room for 
many more. Particular states of a nation may be densely popu- 
lated, and at the same time the general density of the whole 
nation fall far short of over-population. History records very 
few cases of general over-population, but there are numerous 
records of too great local density. 
In the population records of some of the older countries, there 
are cycles which sometimes are so emphasized that we may mis- 
judge the population capacity of the area under normal condi- 
tions. The occasional occurrence of famines in these countries, 
in which the mortality is very high, does not signify over-popu- 
lation; it means primitiveness in sanitation, and an ignorance of 
the cause of disease, a condition that is now approximated in the 
United States in particular diseases, such as typhoid fever, tuber- 
culosis, and syphilis. In North America there are no records of 
famines or plagues since the white men commenced in earnest to 
take hold of the country; stories of famines among the Indians 
are current in legend, and doubtless such famines did exist. 
Density in particular states. From the reports^ of the last 
census it may be inferred that locally we are approaching a 
condition of maximum density. For example, Rhode Island has 
517 people per square mile; Massachusetts has 420; New Jersey, 
337; Connecticut, 230; New York, 191; Pennsylvania, 170; Mary- 
land, 131; Ohio, 117; Illinois, 101. In Europe, Belgium has a 
population of 587 per square mile, and the Netherlands has 408; 
it is about two thousand years since Roman invasion brought this 
part of Europe in touch with the westward movement of empire. 
Less than three centuries have elapsed since a similar movement 
reached New England. 
In the above list, with the exception of Ohio and Illinois, the 
more densely populated states are east of the Appalachians. 
Furthermore, they are in the northern section of the Atlantic 
states, and their density is due not to pastoral or agricultural 
but to manufacturing conditions. In western civilization maxi- 
mum density or great density accompanies a strong development 
^ Henry Gannett, ‘'The Population of the United Std^tes,” National Geographic 
Magazine, vol. xxii, p. 36, 1911. 
