Back then, the "press" was the only method of communication other than actually talking to people. But the point was that the government couldn't infringe a method of communication.

EDIT: Note, for example, that the Federalist Papers that drove much of the discussion behind the policies in the Constitution were self-printed by Franklin, et al. Newspapers at that time were highly political and opinionated, like Fox News today, and did very little actual reporting of news. Journalists and "the press" didn't get conflated until much later.

The point is the government can't arbitrarily take away your medium of communication you legally own and use. Barring random specific issues (such as noise ordinances), if you own a megaphone (metaphorical or not) you can use it to spread your speech. If people could only exercise free speech by whispering quietly to themselves then it may as well not exist. You could start by reading wikipedia about freedom of the press.

That, I already understand. What I'm asking about is the narrower definition of "the press" in that historical context, because the usage nowadays is much broader.