(http://www.cr.nps.gov/history/online_books/hh/13/images/hh13j3.jpg)
A Union Army wagon train entering Petersburg.
Courtesy, National Archives.
I'd point you at Gen. U.S. Grant's Army. His trains were famous. In Mississippi he cut himself loose from both rail and water resupply and carried everything with him. I read somewhere's his wagon trains were over 10 miles long and constantly moving. I think it was some type of an inovation in war making strategy. Nobodied ever purposfully cut themselves loose from their supply line before and it caused a controversy.
I think your boy would've done good to be apart of Grant's Vicksburg Expidition in the spring of 1863. He might even have gotten overrun by Missouri Rebels at Champion Hill and met up with his cousin or someone he know'd from back home.