Help: Trying to remember an old OS

Hello --

I no longer have the phone in question, but I'm trying to remember the OS (either 3.x or 4.x) I had on my 3GS (8GB).

It was an 8GB, Black. Bought it in 2011.

I remember being able set a home wall paper and a lock screen wall paper.
It had auto correct.

Is that enough to determine if it was iOS 3.X or 4.X?
I never updated the OS, so it's whatever it shipped with.