Audrey,
As far as I know there is only one sassafras that grows in our area and is native and that's the Sassafras albidum. Some call it Red Sassafras, some call it White but I don't know that there's a difference at all, except in what it's called. It's a tree of the laurel family, but most of the others of the laurel line are evergreen and sassafras is not.
The only trees I've ever known had the root beer scent and flavor and the three leaf shapes, mitten like but often with fingers.
I think I've made sassafras tea from every sassafras tree that I ever met.
They are beautiful trees; smell good too.