Negroes to
locate themselves within restricted bounds of habitation which
resulted in a great deal of overcrowding among them. There were found
numerous cases in which there were too many persons for each room and
too many for each bed. Instances in this regard will be cited farther
on in this dissertation.

Another effect of the Negro migration was that of increasing the
friction between races in certain parts of the North and West. This
effect, however, was not as extensive as it was once thought to be;
for in many instances Negroes worked and lived peaceably side by side
with the whites. Nevertheless, there were found numerous cases in
which racial friction operated to bring about strained relations
between the two social groups. These manifested themselves in the form
of refusals on the part of some employers to hire Negroes, because
white laborers objected to working with black men, and in the form of
emphatic protests of white residents of certain industrial
towns--especially in the steel districts of Pennsylvania--against the
bringing in of Negroes to live among them. This neighborhood prejudice
existed also in a number of the cities of the North and West, and was,
no doubt, the source of much of the trouble between the races.[113]
The most bitter form of racial friction occasioned through the
migration was that which grew out of economic rivalry and competition
for jobs. This competition was brought about by a policy pursued by
Northern employers, the practice of deliberately importing Negro
laborers from the South to replace white workers who went on strike.
This naturally served to fan the flames of hatred of the white workers
against the Negroes, and actual expressions of this were seen in the
serious race riots which followed.

An example of a race riot which grew out of this economic competition
was that which occurred in Philadelphia, during the early part of
1917.[114] There the white workers in a large sugar refinery went on
strike, whereupon the owners of the plant attempted to break the
strike by the use of Negro laborers. The latter were attacked
violently by the displaced white laborers, and the result was a race
riot in the course of which one Negro was killed, and several others
were wounded. It is said that the whites resented this substitution of
Negro labor for theirs, because the former was being used to keep down
wages and thus destroy unionism.

Another typical example of such a race riot