The Northern Mockingbird is very common in the South. During my stay in Arkansas this summer, it seemed they were everywhere I went. Even before I could get my luggage in the car, the immature Mockingbird was acting out with its parents trying to keep it in check.
The Northern Mockingbird is a long slender bird with many voices. It is named the Mockingbird because it is able to mimic sounds of all kinds from other birds to machinery. Unfortunately, I didn't get to hear any of its vocal but I was very entertained by it bouncy, hopping, tail-flicking behaviour.
This image of the Northern Mockingbird in flight best demonstrates the white wing bars and the two white external tail feathers. This is somewhat like the Dark-eyed Junco's white tail feathers, except these are much longer.