A haversack is a sturdy bag, usually made of canvas or heavy cloth, worn over one shoulder to carry supplies. The bag hangs at your side, leaving your hands free for other tasks. Soldiers have used haversacks for centuries to carry food, water, and personal items during long marches. Civil War soldiers stuffed their haversacks with hardtack (a tough biscuit), salt pork, and letters from home.

Think of a haversack as the great-grandfather of the modern backpack, but worn across one shoulder instead of both. While backpacks distribute weight evenly, a haversack puts everything on one side. Hikers and campers sometimes still use haversacks because they're simple, durable, and easy to swing around to grab something without taking the bag off completely.

The word combines “haver,” an old term meaning oats (food for horses), with “sack.” Originally, haversacks carried feed for cavalry horses, but soldiers soon realized these tough bags worked just as well for carrying their own rations and gear.