Chris, the meaning of "camp ground" could refer to the camp meeting ground, which provided an oasis away from daily cares and, i slavery times, unremitting work.

But I don't think that's the answer.

"Deep River" is often found with the alternate last line:

"I want to cross over in a calm time."

In other words, the singer wants to cross Jordan into the Promised Land, not in the storm referred to in so many gospel songs, but in calm water. My suggestion is that "camp ground" began as a misunderstanding of "calm time."

Bob