Just the framing of the question is insanely insulting nonsense and almost makes me believe this is not a question being made in good faith.

In an attempt to reduce my blood pressure, how bout we go ahead and assume the people enduring slavery were, largely, the same as you and I. Wouldn't you know, they probably could've figured out how sneaking away in the goddamn night works.

Now, let's say you found yourself enslaved, AND knew the one weird trick slave owners hate (waiting until night time). What might keep you from fleeing slavery in this situation?

Maybe, vicious dogs? Or perhaps the threat of being scourged within an inch of your life with a whip? Maybe it's just the fact that any random what person within 300 miles is going to string you up from a tree if they see you out at night?

If all else fails, literally the entire state apparatus will hunt you to the end of their jurisdiction and beyond and make an example of your ass.

There was no getting out. You were property, someone's farm tool. If you didn't understand that, they'd make your life more of a living hell than it already was.