Chaplinsky v. New Hampshire is a foundational hate speech case from 1942, upholding the law prohibiting fighting words.
Walter Chaplinsky appealed the state of New Hampshire’s law regarding calling people names in public. Chaplinsky argued that the law violated the First Amendment right to free speech.
Chaplinsky was a Jehovah’s Witness who distributed pamphlets referring to other regions as “rackets.” He was convicted in a New Hampshire court of using offensive names in public.
The court affirmed the state law’s constitutionality, considering hate speech “fighting words” and therefore considering them an exemption to the First Amendment rule. Free speech cannot be dangerous speech.
It is a statute narrowly drawn and limited to define and punish specific conduct lying within the domain of state power, the use in a public place of words likely to cause a breach of the peace. (google scholar)
This is an important case because it established that there are limits to what a person can say in public. You do have the right to free speech, but you do not have the right to offensive or hateful speech.