What events in the past four years in America might be considered an Incubation period of social discontent?

the following best describes postwar era writers in their works:

many writers,authors,novelists,poets concentrated more on social art and social writing and stayed away from political writings.

1. darius the great     persia  

2. piankhi       nubia

3. ezana       aksum

4.     nebuchadnezzar     babylonia

5. shalmaneser iii     assyria

i'll write a docs for you. hold on for a moment

on april 6, 1917, the u.s. joined its allies--britain, france, and russia--to fight in world war i. under the command of major general john j. pershing, more than 2 million u.s. soldiers fought on battlefields in france.