Prior to about 1915 , one of the most respected and best assimilated immigrant group was the Germans. And yet, with war fever growing, along with spurious reports of German sabotage and actual deaths of Americans on British ships like the Lusitania sunk by German submarines, public opinion turned against residents of German ancestry. As John Higham wrote in his classic, Strangers in the Land, once the United States entered the war:
German societies dared not hold public meetings or outings even in cosmopolitan New York. I]n numerous areas local officials banned the sale [of German-language newspapers]. Before the war ended, some whole states -- Delaware, Iowa, Montana, and others -- banned the teaching of German. German opera was boycotted, sauerkraut became "liberty cabbage," and many towns, firms, and individuals with German names changed them. Theodore Roosevelt advised shooting or hanging any German who showed himself disloyal, and eminent clerical spokesmen demanded the death penalty for German propagandists.It wasn't just government cracking down; these were the actions of hitherto tolerant Americans.
I worry that anti-Muslim hysteria may bring back such dark days.