I think you're right. Try to watch it when it lands. They always flare their tail wide when they land and the sun on it or through it makes their name an obvious choice.
A Red-shouldered Hawk is usually smaller but similar. You can ID them because they call a lot, very vocal birds. The Redtail will usually just call once(it's the cool sound they use for Eagles on TV). The Red-shouldered will have continous calls (kee-kee-kee-kee).