Hardtack or Ship's Biscuit

[major bill]

I assume "hardtack' and "ship's biscuit " are terms for basically the same thing. So when did the term "hardtack" come in to use? Also did the Navy during the Civil War still refer to them as "ship's biscuit"?

 

[major bill]

Ship's Biscuits are also know as 'Cabin Bread', Pilot Bread', or 'Sea Biscuit'. The Russian military still uses hardtack as does the Japanese Ground Self Defense Force. U.S. Army uses MRE bread which is soft bread, but mostly soft bread only in theory. OK modern U.S. Army MRE bread is not that bad but tends to be a bit hard.