Question

Why did Allied forces find so much destruction when they finally reached Germany?
German troops had destroyed the country to prevent the Allies from finding supplies.
German civilians had been rioting to protest the war and the actions of the Nazi regime.
German cities and factories had been destroyed by the many battles between ground troops.
German cities and factories had been destroyed by an ongoing Allied bombing campaign.

Answer 1

German cities and factories had been destroyed by an ongoing Allied bombing campaign. The RAF and USAAF carried out sustained strategic bombing of German industry, communications and urban areas, causing widespread destruction before Allied ground forces reached the Reich.