Which domestic shift most affected the demographic makeup of northern us cities in the early 1900s?
a.
migration of african americans from southern farms to northern factories
b.
influx of illegal immigrants from mexico and central america
c.
discovery of large coal deposits in some midwestern states
d.
us acquisition of puerto rico and the philippines after the spanish-american war
e.
us victory over mexico in the mexican-american war

A.  migration of African Americans from southern farms to northern factories.

Explanation:

African Americans wanted to escape poverty, lack of opportunities and discrimination in the South. Industralization and growing urbanization in the northern states gave them new opportunities and hopes of a better life.

no because we were not ready for war

seeing as no choices were provided, i'll do my best to answer it from knowledge.

job specialization promotes work ethic to the person doing the job. he/she may be strong in the arms and able to lift things, specializing him/her in a job where you lift and carry.