Did the USS Constitution have a bathroom

The museum does have restrooms

Yes

After you go through the Photo ID point, the Visitor Center/ souvenir shop has restrooms right after you pass through the doors.

Not on the ship , but in the Museum

Museum next door

Not on the ship, it's in the museum once you enter it where you go through first before you can go out (again) then go the USS Constitution a few yards away.

Mister let is right on its approximately 50 yards from the ship to the museum area where the restrooms are

The ship no....but Museum does