Carl, if I may . . . I think Old Pete is referring to the bag under the canteen. I seen that bag called the "haversack" in many/most sources.
Notwithstanding Pete's comment, we can't know that SOME Union soldier didn't have a cloth bag, instead of the black-painted oil-cloth one he was most likely issued. Maybe the quartermaster of the 59th New York regiment ran out of black ones, and issued whatever he could get his hands on. Maybe the soldier's mother/sister/wife/girlfriend made him a bag, and he carried that instead of the one he was issued. His great grandfather may have carried a home-made one like it during the Revolution, and if it was good enough for Great Gran-dad, it is surely good enough for this soldier.
Anyway . . . great job on such a big figure!