The Bald Eagle was a 4 year old male, this is quite young as these birds live to be 30-40 years old. The head and tail feathers of very young birds are totally brown, as they get older they go white. This young bird is still changing and that's why he has the brown streaks, his head will be all white as a fully mature adult.
Notice the unique eyebrow over the eye which shades and protects it. I had never really noticed this little skin flap until I saw it in this picture.
And my very favourite shot of all:
What a majestic bird, I was thrilled when I saw this shot! Not enhanced in any way, straight from the camera. The National bird of the United States (good choice!!).