During his command in World War I, Pershing rejected British and French demands that American forces be integrated with their armies, essentially as replacement units, and insisted that the AEF would operate as a single unit under his command, although some American divisions fought under British command, notably in the Battle of Hamel and the breaching of the Hindenburg Line at St Quentin Canal, precipitating the final German collapse. Pershing also allowed (at that time segregated) American all-Black units to be integrated with the French Army.