1. The increase in U. S. manufacturing was a direct effect of what war?

World war 1

Explanation:

In world war 1 american industry boomed and in just four years, US exports to Europe rose from 1.479 billion dollars to 4.062 billion dollars

(The question is asking which war caused increase in U.S manufacturing right?)

lincoln declared that slavery should not be allowed to spread into the new states, and of course this angered the south at the time.

the second significant cause of the great migration was the desire of black southerners to escape segregation, known euphemistically as jim crow. rural african american southerners believed that segregation - and racism and prejudice against blacks - was significantly less intense in the north.