If you're talking about World War I then the federal government implemented the Espionage and Sedition acts. These laws limited the freedom of speech for American citizens. The Espionage and Sedition Acts allowed for the arrest of individuals who spoke against the war effort or promoted avoiding the draft.
If you're referring to World War II, Japanese-American citizens had their freedoms limited after the attack on Pearl Harbor. After the attack by the Japanese military on Pearl Harbor, President Franklin Roosevelt issued Executive Order 9066. This allowed the government to forcibly remove any individual in a military area. In this case, Japanese-American citizens are removed from their homes on the West Coast and forced into internment camps. These internment camps were restrictive, as Japanese-American citizens could not leave and return to their homes until the war is over.
