Accoutrements helped the Soldier of the Civil War to survive long grueling marches and to fight when the time came. These items were vital to the soldier's survival; the haversack held his plate, eating utensils, and assorted personal comfort items such as letters, books, pictures, and tobacco, his canteen for his much needed water, and his blanket for the night chill. Other accoutrements held the instruments of War, such as the deadly bayonet and bowie knife, or the cartridge box with its supply of bullets and gunpowder.

Knapsack and Blanket Roll
http://www.26nc.org/Articles/knapsack%20and%20blanket%20roll.pdf