They say 2 years is the recommended age to forward face. But, that's just a suggestion and not a law (yet -- and not in GA). I just turned my 15 month old around to forward on our last road trip -- she stopped screaming and crying immediately -- she wanted to see us and know what was going on. Also, it gave me ans my husband a break from the fussing while stuck on the interstate for an hour due to traffic detours. I'll most likely get judged for it, but I don't care.
I did at 1 with all 3 of my kids. But like @tasticmel said which state is different. Arkansas just passed or trying too pass the law that the child has to be 2.