Attached is VANITY FAIR article from 1917 covering the social and patriotic transformation of New York City during World War I:
"New York in war time has revealed herself in her true light. She has shown an adaptability to strange and trying conditions which has surprised even those who knew her best... If the Kaiser is a bad sleeper, and he ought to be, he must be haunted in the mid-hours of the night by visions of the skyscrapers of lower Manhattan Island, for they symbolize the staying power which he should dread most of all."
Click here to read further about New York during W.W. I.
Click here to read about the welcome New York gave Sergeant York.
An additional event took place in 1917: Congress granted full U.S. citizenship rights to the citizens of Puerto Rico - but they didn't move to New York until the Fifties. Click here to read about their integration.