Hardtack and Coffee or The Unwritten Story of Army Life (1887) is a memoir by John D. Billings. Billings was a veteran of the 10th Massachusetts Volunteer Light Artillery Battery in the American Civil War. Originally published in 1888, Hard Tack and Coffee quickly became a best seller, and is now considered one of the most important books written by a Civil War veteran. 'Hard Tack and Coffee’ is not about battles, but rather about how the common Union soldiers of the Civil War lived in camp and on the march. What would otherwise be a mundane subject is enlivened by Billings’ humorous prose.