Which of the following events caused immigrants to migrate north after the civil war? a. the passage of the homestead actb. the emergence of industry in citiesc. advances in the printing industryd. the completion of the transcontinental railroad

B. The emergence of industry in cities

Explanation:

After the Civil War, the North became an industrial powerhouse. Cities such as Chicago, New York, Philadelphia, Baltimore and Boston attracted immigrants, both from other parts of the U. S. and from Europe.

African Americans in the South, who had recently been slaves, continued to live in poverty in the agricultural South, and many of them began to migrate North to find job in the industrial cities. This event is known as the "Great Migration", and is the origin of the large African American Population in most of America's big cities.