sion of the French. Later, when a growing population pressed
against the western barrier, mountain gates opened at Cumberland Gap and
the Mohawk Valley; the Ohio River and the Great Lakes became interior
thoroughfares, and the northwestern prairies lines of least resistance
to the western settler. Rivers played the same part in directing and
expediting this forward movement, as did the Lena and the Amoor in the
Russian advance into Siberia, the Humber and the Trent in the progress
of the Angles into the heart of Britain, the Rhone and Danube in the
march of the Romans into central Europe.

[Sidenote: Segregation and accessibility.]

The geographical environment of a people may be such as to segregate
them from others, and thereby to preserve or even intensify their
natural characteristics; or it may expose them to extraneous influences,
to an infusion of new blood and new ideas, till their peculiarities are
toned down, their distinctive features of dialect or national dress or
provincial customs eliminated, and the people as a whole approach to the
composite type of civilized humanity. A land shut off by mountains or
sea from the rest of the world tends to develop a homogeneous people,
since it limits or prevents the intrusion of foreign elements; or when
once these are introduced, it encourages their rapid assimilation by the
strongly interactive life of a confined locality. Therefore large or
remote islands are, as a rule, distinguished by the unity of their
inhabitants in point of civilization and race characteristics. Witness
Great Britain, Ireland, Japan, Iceland, as also Australia and New
Zealand at the time of their discovery. The highlands of the Southern
Appalachians, which form the "mountain backyards" of Kentucky, Tennessee
and North Carolina, are peopled by the purest English stock in the
United States, descendants of the backwoodsmen of the late eighteenth
century. Difficulty of access and lack of arable land have combined to
discourage immigration. In consequence, foreign elements, including the
elsewhere ubiquitous negro, are wanting, except along the few railroads
which in recent years have penetrated this country. Here survive an
eighteenth century English, Christmas celebrated on Twelfth Night, the
spinning wheel, and a belief in Joshua's power to arrest the course of
the sun.[75]

An easily accessible land is geographically hospitable to all
new-comers, facilitates the mingling of peoples, the excha