The question as phrased probably can't be answered, but a few related data points:
As mentioned in the comments, passwords on all IBM 3270-style terminals are usually entered in fields with an "invisible" attribute. In practice, that means you can see the cursor moving, and as the password field is usually below some other field, e.g. the username, it's also pretty easy to count characters. I would count this definitely under "visual feedback".
The NOS Interactive Facility would present a "character salad" on the teletype, which you'd then overtype with your password (see page 2-6). Which, like above, means you'd see the printing head move, so you could count characters, but you couldn't read the character you typed. I'd consider this as the same kind of "visual feedback". This may or may not be the system mentioned in the comments.
The manual is from 1979, but I would assume this feature was present in earlier versions as well.
Incidentally, the Plato System, which ran on NOS, and had a special video terminal, displayed one or two
X for each character that you entered as a password. So this is a variant: visual feedback, but it doesn't allow an onlooker to count the characters in the password, but it also makes it harder for the user to verify if the password he types is correct.
In general, typing passwords only makes sense on multiuser timesharing systems, so the first such system (whatever it is) would provide a lower bound. Given that many teletypes had local echo, printing asterisks instead of chars (and removing them on backspace) makes more sense for videoterminals, so if you are applying stricter criteria, that's another bound.
The rationale for providing any kind of feedback for password entry should be pretty obvious: It makes mistakes less likely. So the design space is somewhere between "not implemented because there's always local echo, we must use some other way" over "let's provide an invisible attribute in our video terminal" to "all echoing is done by the host anyway, and we've plenty of memory, so why not make it more comfortable for the user?"