Only The Philadelphia Depot produced the corrugated canteens for issue via contractors, though there had been some militia canteens that had the concentric rings prior. The smooth spheroid canteens were easily dented, causing complaints from the field, thus on July15, 1862, the Philadelphia Depot announced that they would specify the corrugated canteens moving forward. (Letter from Col. Crossman to contractor Paul J Field, July 15, 1862, in the National Archives)