That's a good possibility. He lived in Vicksburg with his uncle, Daniel Swett. Although Rockwood is not found on the census, I did find Dan'l Swett, household #650. Swett is found alone on the census, although his wife, Sarah, was certainly alive at that time. The listing is also odd in that it does not list his age, sex, race, or state of birth. It states that he is a farmer with real property worth $4,000, but with no personal property listed. This listing, taken on June 29, 1860, would leave me to believe that no one was home, and that the census taker wrote down what he knew about Daniel, and did not record anything else. That could possibly fit with your theory, in that the entire household may have been traveling together.