What were hard tack?

Hardtack is a type of dry, flat biscuit made from flour, water, and sometimes salt, historically used as a staple food for sailors and soldiers due to its long shelf life. It was often hard and difficult to chew, requiring soaking or boiling before consumption. Hardtack became particularly notable during the 19th century, especially in military contexts such as the American Civil War, where it was a primary source of sustenance. Its durability made it ideal for long journeys and harsh conditions, though it was often criticized for being bland and unpalatable.