Hard Tack and Coffee: 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. The book is abundantly illustrated by the pen and ink drawings of Charles W. Reed, also a veteran, who served as bugler in the 9th Massachusetts Battery, later received the Medal of Honor for saving the life of his battery commander at Gettysburg.