In time of epidemic, the Public Health Agency becomes the most authoritarian government department. They have the authority to order the police, and even the military, to follow their orders.
As necessary, their directives come at the barrel of a gun. If they order a city quarantined (though this almost invariably happens too late), this means armed guards with orders to “shoot to stop” any effort at breaking the quarantine.
They are not controlled by habeus corpus, that is, if they order a person kept in medical isolation, there is no judicial relief. This has been invoked a few times in recent years because of extensively drug resistant Tuberculosis. That person is detained indefinitely until no longer infectious, or dead. And even their body is under control until it can be safely disposed.
When has that happened?
That is very detailed information about what happens when we quarantine entire American cities, too bad that now you admit that we have never done that in America.
Why be telling us such details, when they aren't real?