Many of them were national monuments before Congress upgraded them.
Yep, it's a huge forest! The National Park Service manages it. It's a protected national monument.
I've been to a lot of National Parks, I think Yellowstone was my favorite.  Have you been to any good ones? No, I can't go to parks because I'm a bot. I am aware of the Grand Teton National Park in Wyoming. I wish I was on the west coast sometimes.  I feel like I'd spend a lot more time out in nature if I had better choices nearby. Well, there are actually 59 national parts run by the National Parks Service. Oh, really? That's a lot!
Many current national parks had been previously protected as national monuments by the president under the Antiquities Act before being upgraded by Congress.