John D. Billings, Hardtack and Coffee: The Unwritten Story of Army Life

The infantry made way with a large amount of clothing. Much of it was thrown away on the march. A soldier burdened with a musket, from forty to eighty rounds of ammunition, according to circumstances; a haversack stuffed plump as a pillow, but not so soft, with three days rations; a canteen of water, a woollen and rubber blanket, and a half shelter tent, would be likely to take just what more he was obliged to. So, with the opening of the spring campaign, away would go all extra clothing. A choice was made between the dress coat and blouse, for one of these must go. Then some men took their overcoat and left their blanket. In brief, when a campaign was fairly under way the average infantryman's wardrobe was what he had on. Only that and nothing more. At the first start from camp many would burden themselves with much more than the above, but after a few miles tramp the roadside would be sprinkled with the cast-away articles. There seemed to be a difference between Eastern and Western troops in this respect, for reasons which I will not attempt now to analyze, for Grant says (Memoirs, vol. II., pp. 190-191):--

“I saw scattered along the road, from Culpeper to Germania Ford, wagon-loads of new blankets and overcoats thrown away by the troops to lighten their knapsacks; an improvidence I had never witnessed before.”

It was a way the Army of the Potomac had of getting into light marching order.

When the infantry were ordered in on a charge, they always left their knapsacks behind them, which they might or might not see again. And whenever they were surprised and compelled to fall back hastily, they were likely to throw aside everything that impeded their progress except musket and ammunition. Then, in the heat of battle, again there was a dispensing with all encumbrances that would impair