Union Gen. William Tecumseh Sherman had long known that his fragile supply and communication lines through Tennessee were in serious jeopardy because of depredations by Forrest's cavalry raids.(Battle of Brice's Crossroads).
The depredations of a person, animal, or force are their harmful actions, which usually involve taking or damaging something. Much of the region's environmental depredation is a result of poor planning. an act of taking or destroying something (déprédation, from depraedari )