Carl von Clausewitz 
On War: All Volumes 

Carl von Clausewitz ( 1780 – 1831 ) was one of the most influential military figures of the 19th century. Clausewitz was a Prussian soldier and German military theorist who stressed the importance of the moral and political parts of war. Clausewitzs famous treatise On War is considered one of the most important military treatises ever written. Generals who fought in the Civil War often carried a copy of the treatise to touch up on strategies and tactics.