muggers

[donna]

muggers Came into general use during the Civil War, meaning the same as it does today: prisoners who jumped other prisoners and robbed them of valuables such as blankets, clothing, tradable items, or food. Often occurred as a "fresh fish"(brand-new prisoners; new arrivals to the prison facility) first entered the compound-if done anytime later, it was referred to as a raid.

From: "Portals To Hell" by Lonnie R. Speer, "The Language of The Prison Camp", page 316.