What restrictions were caused by war and restrictions were lessened by it?

In World War I their was a great influx of emigrations to the United States that preceded the immigration restriction laws. "The war itself, although it sharply decreased migration from Europe, nevertheless created a climate of opinion favorable to restriction."(Hutchinson) This led into the creation of two Quota Acts, the first which received a pocket veto from the President but was later signed and the second one that passed with support from much of Congress and the President. Both were put in place to determine the amount of people that could come to America and from where. The original Act allowed 3% of the nation to be people who immigrated, but the 2nd Act lowered it to 2% because the restrictive legislature did not seem to be doing enough, in terms of lessening the immigration's per year. This legislature was not changed until the discriminatory legislature was brought to public eye and shown the real nature of those laws. The effect of the Civil War on the U.S. was an entirely different outcome where most of the populace that had owned slavers, were actually in need of more labor and more immigration's to the U.S.  The times during Reconstruction were problematic because of the complications that arose from lack of previous workers(blacks) and not enough immigration into some of the states that had been slave states. "Many believe that on account of a low birth rate and the emigration of Negroes, labor would become so scarce as to make imperative the introduction of outsiders."(Woody) This fear was that the emigrations from the U.S. would not equal out with the immigration's into the U.S. The restrictions were lessened after the end of the Civil War and the hostile tensions between Americans and immigrants ceased as the U.S. was still recuperating from the Civil War.