World War 1.
Many blacks left southern states during WW1 and moved to big northern cities to work in war industries.
More went to New York city than to any other,and after the war there a lot of blacks living in Harlem who were literate and artistic.
i would say primary, but it could be secondary im not completely sure.
hope that helps xx
It means "year of our lord" in Latin, meaning the number of years since Jesus.
The years before the AD ones are labeled 'BC', for "Before Christ".
Both of those labels are the reasons why many people, especially
non-Christians, such as for example Jews and Muslims, prefer to
label the years as 'BCE' and 'CE', meaning "Before the Common Era"
and "Common Era".
During the first 50 years of the nation, diplomats were guided by the idea that the United States should observe political isolation from European powers during peacetime and maintain strict neutrality during periods of war.
