Why did wagon trains struggle to support rapidly advancing armies?

Wagon trains struggled to support rapidly advancing armies primarily due to the inherent limitations of animal-drawn transport and the logistical burden of the supply chain itself.12

Key factors included:

• The Shuttle Multiplier: To maintain a flow of supplies, wagon trains had to operate a continuous shuttle. Because the transport personnel and animals required their own food and forage, the further an army moved from its base, the more the supply train consumed its own cargo. For every day of travel time, two vehicles were effectively needed to deliver a single load, creating a "multiplier factor" that set strict limits on an army's operating radius.2
• Forage Requirements: Before mechanization, forage was the bulkiest and most critical supply item. An army’s animals needed to be fed regardless of whether the army was moving or stationary. At significant distances, the forage required to sustain the transport animals would saturate the entire capacity of the wagon train, leaving nothing for the fighting force.32
• Speed and Rigidity: The staged resupply system, which relied on these trains, was designed for slow, steady advances along predetermined routes. These systems lacked the flexibility to keep pace with rapid maneuvers, often causing fast-moving forces to outrun their supply lines.12