The Civil War brought unprecedented challenges to military and political officials on both sides. One of the key questions was how to instill discipline upon largely volunteer troops. Confederate and Union armies were primarily made up of amateurs, men who proudly believed in the ideal of the citizen soldier, but who often defiantly pushed back against conventional army regulations. This chapter narrates the efforts of the Union and the Confederacy to instill discipline and training, especially when faced with varying degrees of demoralization and disaffection. It further explores how and why commanders and soldiers adapted (or failed to adapt) to these codes of conduct, punishments, and the wider repercussions for Americans largely unused to the strict demands of wartime service.