Why are mourning doves illegal to own?

I had a wild mourning dove for 13 years. He travelled everywhere with me. He lived in a huge dog kennel in which the door was ALWAYS left open to. He had free reign within all the apartments I lived in. He was well fed and incidently, we were both best friends. That bird had his own personality. We truely had a bond. It breaks my heart that people can go out into a field and murder these magnificent creatures and not even eat them if they choose. I can't welcome one into my home to live with me. No, not as a pet, but as a friend. His name was Sandalwood. His friendship was more wonderful and lasting than any human friendship I've ever know. Why is it legal to murder a such a beautiful bird, but illegal to be friends with one and have as a roommate? Its heartbreaking to me. I really miss him.