How did World War I and its aftermath affect freedom and civil liberties in the United States? For whom?

World War I and its aftermath greatly curtailed civil liberties in the United States, with everyday citizens and dissidents who were not in support of the war being most greatly affected. The main vein of civil liberties to be diminished dealt with First Amendment rights, with freedom of speech and freedom of the press being reduced as a result of the war. President Woodrow Wilson attempted to suppress opposition and dissent among American citizens, as the American government did not want anything to hamper victory over the Central Powers.
Legislation and court cases weakening civil liberties included the Espionage Act, which was appealed and eventually wound up in the Supreme Court as Schenck v. United States. In the case, Schenck was convicted of attempting to obstruct the draft because he distributed pamphlets which denounced and discouraged the draft. The Supreme Court upheld his conviction, with the Court citing the "clear and present danger" of a crime being committed that would negatively affect national security as the basis for the decision.
The Trading with the Enemy Act and Sedition Act were two pieces of legislation enacted to severely quash any anti-war sentiment. The Trading with the Enemy Act affected businesses and trade to a certain extent, but it affected individual freedoms by censoring materials that were imported from and exported to all foreign countries. An example of items censored under this act were Socialist mailings and pamphlets.
Under the Sedition Act, the government could imprison an individual for any “disloyal, profane, scurrilous, or abusive language” aimed at the government, governmental policies or positions, or even the American Flag. The Sedition Act was also appealed and wound up in the Supreme Court in the case Abrams v. United States. The Court upheld the law even though it was viewed by many as too broad and ambiguous in nature; essentially anything remotely non-supportive of the war effort could be construed as breaking the law.
Strassfeld, Robert N. "Espionage Act (1917) And Sedition Act (1918)." Major Acts of Congress, The Gale Group, 2004.