It appears there is a mix-up in the details you've provided. Fort William Henry, located in present-day New York, was besieged during the French and Indian War, but the events you're referring to occurred in 1757, not 1758.
In August 1757, the French forces, led by General Louis-Joseph de Montcalm, besieged and captured Fort William Henry. The British garrison, numbering around 2,000 troops, was eventually forced to surrender after a prolonged siege. The defeat was significant for the British, as it allowed the French to strengthen their control over the strategic waterways in the region.
The incident is often remembered for the subsequent massacre of British prisoners by Native American allies of the French after the surrender, which heightened tensions between the British and Native American tribes.
If you need more information on this topic or related historical events, feel free to ask!