I'm no expert with birds, esp not American ones, however this one is certainly a puzzler to me.
It's almost certainly a juvenile something and that makes it tricky as quite a few can look similar at that transitional stage in life.
The only thing that makes me wonder if its not an eagle (either bald or ) is that the beak just seems, in the photos, to be a touch too small/dainty compared to a more broad/bigger eagle beak.
A bald eagle has an all yellow beak, whilst juvenile should be all dark, so if this is one then its right in the transitional stages it would seem changing from black to yellow (note I've no idea how this transition occurs, however the bird above has a very clear line between the two colours rather than a gradual shift in tone)
Beak wise I'd say it looks closer to a golden eagle, but the legs don't look right as this bird has quite clear bare lower halves to its leg/shin rather than covered all the way to the talons. This lack of feathering there also messes it up being a rough legged buzzard, although most of the other colours and markings and beak look quite good for that match up.
The best match up I can work out is a red-tailed hawk of the harlani variation, which does winter in southern USA. This guess would actually go against my gut feeling of it being a juvenile and it could be an adult. However the book does state that it can be confused with a few other species so whilst this appears to fit the picture best it might not be what it is.
Based on its apparent size I'd be happier classing this as a hawk over an eagle, but such characteristics from a non-expert and from a photo and picture ID are not reliable. Suffice to say I'd say its between bald eagler and the red-tailed hawk variation