I don't know what got deleted and what the fight is/was about, but here is a general example how freedom of speech normally works and what its limits are:
Imagine you invite me into your home, and after a while i start ranting about how ugly your living room is. I just can't stop and go on and on. Finally you had enough and ask me to leave. Then I would say "NO! Freedom of speech! You can't make me leave your house!" That wouldnt make sense, right?
Same with this site. This is not a public space. When you created your account, you accepted to follow rules. I assume you didn't follow them, so that post of yours got deleted. This is all perfectly fine under the freedom of speech, the same way you wouldn't have to suffer me ranting about your living room for hours.
Also, this is the Internet, not America.