Hi Patti- Not from first hand knowledge but this is very close to Sibley's drawing of an immature White-tailed Kite Elanus leucurus. Adults would lack the reddish brown around the head, upper breast and back.
Dan, Isaac and John, Thanks much. I was looking at the Kites because of all the white, but I was fooled by all of the brown and detail on the wings. None of my books show that, not even on the juveniles.