In Frohwerk v. United States (1918), the U.S. Supreme Court upheld Jacob Frohwerk's conviction for violating the Espionage Act of 1917, which made it a crime to interfere with military operations or support America’s enemies during wartime. The case revolved around twelve articles written by Frohwerk in a Missouri newspaper that criticized American involvement in World War I and encouraged resistance to the draft. The court ruled that these publications had indeed interfered with recruitment efforts and could potentially incite insubordination within military ranks, thus constituting an offense under the Espionage Act. In its decision, the court emphasized that freedom of speech does not include immunity for every possible use of language; this was particularly true when such usage posed clear threats to national security during times of war.

In the case of Frohwerk v. United States, there was no dissenting opinion recorded from any justice. The Supreme Court unanimously upheld Jacob Frohwerk's conviction for violating the Espionage Act by publishing articles criticizing U.S involvement in World War I, stating that such actions could obstruct military recruitment efforts and thus posed a clear danger to national security during wartime.