Best National Park with a 13 month old?

Hi all, looking into planning a summer trip and would love to get to a National Park. Our babe would be 13-14 months at that point. We love to hike (we have the Osprey poco) and camp, but haven't attempted backpacking with the baby. Husband and I have been to Olympic, Yosemite, and Acadia before (but open to returning) but prefer slightly less crowded spots when possible. Open to any/all ideas! TIA!