"Does not have it's eyes open"??? That's probably not good, even though it's just a hatchling it should have it's eyes open... But it may just be scared... with it being that small there should be others from the clutch around as well... It's probably an eastern box turtle.
I'm going to assume it's a land species since you didn't mention finding him near water.. If you're planning on keeping him, for nutritional purposes, it's probably best to try and get him on a pellet food from the start.. You need to get a good quality pellet mix, soak a few in water and leave them close to the baby and a few around the habitat... Baby land turtles are VERY shy, and he won't eat if he's being watched... You need to give him leaves and stuff to burrow under and hide in... Google "Care Baby Turtles", and read through some of the top sites... You have a lot to learn if he's to survive in captivity.
I'm going to assume it's a land species since you didn't mention finding him near water.. If you're planning on keeping him, for nutritional purposes, it's probably best to try and get him on a pellet food from the start.. You need to get a good quality pellet mix, soak a few in water and leave them close to the baby and a few around the habitat... Baby land turtles are VERY shy, and he won't eat if he's being watched... You need to give him leaves and stuff to burrow under and hide in... Google "Care Baby Turtles", and read through some of the top sites... You have a lot to learn if he's to survive in captivity.