The year is $1930.$ A person in a heavily crowded theater is bored with the play they are watching. So the person decides to make things a little more interesting and starts yelling "Fire!" in front of the large audience even though there is no legitimate fire. Given the year is $1930,$ is this speech "protected" speech under the $1$st Amendment?

No$,$ this is not protected speech under the $1$st Amendment at that time as it represents a "clear and present danger" because it is false speech.

Yes, this is protected speech under the $1$st Amendment and cannot be punished by the government.