There were numerous changes in immigration policies that allowed a certain number of migrants to easily come into the United States. However, Nativist Anglo-American Protestants organized in mass numbers to suppress the huge influx of immigration process and the block the efforts for an immigrant to be a citizen. The biggest fear was the economic competition and religious belief in the spreading of Catholicism.
During wartime, many feared of a subversive potential of spies infiltrating in the country. This led to the passing of the Alien Enemies Act of 1798 which enabled government authority officials to detained and deport "aliens" from the United States.
Let us keep reminding ourselves that American ports were receiving its first waves of immigrants; 31 Million between 1860 - 1930 arrived here.
" Meanwhile, American ports began receiving the first waves of an enormous and transformative mass migration — some 31 million between 1860 and 1930. They represented a “new” immigration: Chinese, Italians, Greeks, Poles, Russians, Syrians, Slovaks, Serbs, Armenians. To many so-called “old stock” Americans, millions of these newcomers were dangerous and unworthy, and to the members of an Immigration Restriction League – which included in its number many of “the best people” of New England – the immigrants were of the “wrong” religions and nationalities."
This way of thinking was really troublesome and if the Nativist Anglo-Americans Protestants would have gotten their way, many immigrants would have had to wait over 21 years to apply for citizenship.
These restrictions implemented on those days seems to be repeating itself all over again in today's world just repackaged and named something else.
Reference
Gerber, David A. "American Immigration: A Very Short Introduction." Oxford University Press, 2011, pp 20 - 21.
Weisberger, Bernard. "For Immigrants - And All of Us - A Time To Fight" Retrieved from https://www.commondreams.org/views/2015/09/15/immigrants-and-all-us-time-fight