Welcome to Coin Talk. The coin has been counter stamped with a metal stamp. It is post mint damage, not a mint error. It is worth face value.
Yes, the mint doesn't do that. It is the first Presidential dollar that I have saw counterstamped though. Spend that one! It looks like its been in use a bit also so it's only worth face value.
Damaged. I could say that since the 28 is raised it is the US Mint's way of counting the coins they produce but that wouldn't be true. Welcome to CT.
The top photo looks included but it's dark. I'm looking at the second photo and with the light it looks raised.
Well.. that is obviously a counter stamp. Sorry you don't see it that way. To add numbers is kind of tricky but this is not the case.
I can't figure out why it looks raised to me, it just does. I know it can't be raised but it looks it, at least to me. Maybe I need a nap.
Oddly Madison passed on the 28 day of June at the age of 85. The number 28 may be symbolic to the day he checked out.
It probably has something to do with the lighting in the photo. The photo with the coin closer up looks to be direct lighting giving the illusion the number is in relief (no shadow). It is definitely incuse. The photo that is a bit darker really shows the number punched in to the coin.
It's a trick of the eye. Depending on your perspective or expectation it can appear raised but it is stamped onto the coin.
