When Thomas Jefferson wrote the Declaration of Independence, he included in it a list of the colonists' grievances with the British government. Notably absent were any complaints that the British government infringed upon the freedom of speech.
In those days, public speech was as acerbic as it is today. If words were aimed at Parliament, all words were lawful. If they were aimed directly and personally at the king — as Jefferson's were in the Declaration — they constituted treason.
Needless to say, Jefferson and the 55 others who signed the Declaration would all have been hanged for treasonous speech had the British prevailed.
Of course, the colonists won the war, and, six years afterward, the 13 states ratified the Constitution. Two years after ratification, the Constitution was amended by adding the Bill of Rights. The first ratified amendment prohibited Congress from doing what the colonists never seriously complained about the British government doing — infringing upon the freedom of speech.
James Madison, who drafted the Bill of Rights, insisted upon referring to speech as "the" freedom of speech to emphasize that it preexisted the government. If you could have asked Madison where he believed the freedom of speech came from, he'd have said it was one of the inalienable rights Jefferson wrote about in the Declaration.
Stated differently, each of the signatories of the Declaration and ratifiers of the Bill of Rights manifested in writing their unambiguous belief that the freedom of speech is a natural right — personal to every human. It does not come from the government. It comes from within and cannot be taken away by legislation or executive command.
Yet, a mere seven years later, during the presidency of John Adams, Congress enacted the Alien and Sedition Acts, which punished speech critical of the government.
So, how could the same generation — in some cases the same human beings — that prohibited congressional infringement upon speech have enacted a statute that punished speech?