I made a fun timeline wall for our house with our Classical Conversations' timeline cards. Enjoy:
The cards are velcroed on with small round tabs that you can purchase at Staples or Office Depot.
The boards are standard trifold foam presentations boards. The dimension of each board is exactly 3ft by 4ft. For space reasons, the last board I cut to fit in place. 160 cards will fit on the 5 boards as seen here. There are 161 cards so the last card does not fit. The tri-fold foam boards are also velcroed to the wall so that I can remove them if I need to. You can teach your own toddlers not to pull the cards off, but you may not want to spend your time training visiting toddlers, in which case it would be nice to remove the boards on occasion.