What were foraging parties during the civil war?

Answer 1

When the armies were on the move, there always had to be expeditions to find food and water for the troops.

The foraging parties were particularly active in Sherman's crossing of Georgia, as these were punitive raids, and the foraging parties were told to burn whatever food they didn't need for themselves.

This hit the local people especially hard, because they were being starved, while the armies had more food than they could consume. This encouraged a lot of lawless mounted hooligans called the Bummers to ride alongside the armies for the free food.

It was the Bummers who committed most of the violence against civilians, which had been strictly forbidden by Sherman. Thus the people of Georgia paid a heavy price for their earlier arrogant attitude in quitting the USA.