re: What kind of bird is this?

Sharp-shinned and Cooper's Hawks can be notoriously difficult to tell apart.

They overlap in size, with female Sharpies sized the same as a male Cooper's, and size is always a challenging field mark without reference, so that's not helpful here.

Tail shape is important, as are legs and the back of the head, none of which we can see here.

Coopers are the more common species in the south in the summer, but in Huntsville you are within range for a summer Sharpie.

Best ID mark we have in your pic is a hint of the color at the back of the neck. A Cooper's Hawk has a dark cap and pale nape, while a Sharpie has more of a hood, with the same color extending from the top of the head to the bird's back.

TLDR: either a Cooper or Sharpie but I'm not making the call