1. Numerical Superiority: The British forces under Cornwallis were outnumbered by the combined American and French armies. The Americans had approximately 12,000 troops, while the French contributed about 7,800 soldiers. Cornwallis's army, on the other hand, numbered around 7,000.
2. Depletion of Supplies: The British supply lines were disrupted by the French navy, which blockaded the Chesapeake Bay and prevented Cornwallis from receiving reinforcements or provisions. This shortage of supplies weakened the British position and made it difficult for them to continue the siege.
3. Encirclement: The American and French forces effectively surrounded Cornwallis's army at Yorktown. The Americans moved to block Cornwallis's retreat to Gloucester Point, while the French positioned themselves on the opposite side of the York River, preventing any escape routes. This encirclement left Cornwallis with few options.
4. Loss of Morale: The British soldiers were demoralized by the continuous bombardment of the American and French artillery, as well as the knowledge that their situation was increasingly dire. The morale of Cornwallis's army further deteriorated as they realized the futility of their position and the unlikelihood of receiving help.
5. Diplomatic Pressure: The British government recognized the strategic significance of Yorktown and the potential consequences of losing the war in North America. With the odds stacked against them and the potential for further political and economic damage, the British government pressured Cornwallis to seek terms for surrender rather than risk a disastrous defeat.
6. Limited Strategic Options: Cornwallis's options were severely limited. Attempting to break through the siege would likely result in heavy casualties, while remaining in the fortified town without supplies would lead to starvation. Cornwallis understood the precarious nature of his position and eventually concluded that surrendering was the most pragmatic decision.
In light of these factors, General Cornwallis decided to surrender to the American and French forces on October 19, 1781, effectively ending major combat operations in the American Revolutionary War.