Upvote:1
I don't recall exactly how it came but I do recall that I didn't immediately recognize it was the passport despite knowing it was coming.
Upvote:2
It has been a couple of year since my last renewal, but it came in a simple envelope, no words on the outside other than address information. Though it is pretty easy to guess if you handle the envelope.
Upvote:8
It should come to you in a large priority mail envelope (like this, or here's a fragment of one that is actually from a passport renewal). It won't say "here's your passport" on it in giant letters, but it will be clearly marked as coming from the US Department of State. If you paid for overnight delivery, I believe they send it FedEx Overnight in a FedEx envelope instead.
Here's a picture of what the envelope looks like: Photo credit: Michael Hampton
If you sent in any documents that get returned to you, such as an old passport, they usually send that back to you separately via First Class Mail in a brown envelope.