It started sometime in 2001. I bought 3 packs from Rite Aid and pulled the Timeless Teams Joe Dimaggio, in the car no less. The last card I picked up in this set was the Jackie Robinson. Damn tough to find all 39 cards.
I still have a ways to go on the Timeless Teams Combos set. If you see any... send 'em my way!
Here it is in the box with most of the base set and inserts.