I was chosen by the Duke Talent Search also. But it must have changed since I was in it. I looked at the link, and the details don't look quite the way I remembered.
I was, along with several classmates, given the option of taking the ACT or SAT in 7th grade. I chose the ACT and I scored an 18, which is pretty good for someone who wasn't in HS yet.

I was still in Louisiana then, also.
Edit: never mind, I see they still have the 7th grade Talent Search, which is what my school participated in, rather than the 4th/5th grade version.