By 11:00 am on the 3rd of July 1754, Louis Coulon de Villiers came within sight of Fort Necessity. At this time, the Virginians were digging a trench in the mud. The pickets fired their muskets and fell back to the fort, whereupon three columns of Canadian soldiers and Indians advanced downhill towards the fort. However, Coulon had miscalculated the location of the fort and had advanced with the fort at his right. As Coulon halted and then redeployed his troops, Washington began to prepare for an attack.
 
Coulon moved his troops into the woods, within easy musket range of the fort. Washington knew he had to dislodge the Canadians and Indians from that position, so he ordered an assault with his entire force across the open field. Seeing the assault coming, Coulon ordered his soldiers, led by Indians, to charge directly at Washington‘s line. Washington ordered the men to hold their ground and fire a volley. Mackay’s regulars obeyed Washington’s command, and supported by two swivel cannons, they inflicted several casualties on the oncoming Indians. The Virginians, however, fled back to the fort, leaving Washington and the British regulars greatly outnumbered. Washington ordered a retreat back to the fort.

Coulon reformed his troops in the woods. The Canadians spread out around the clearing and kept up heavy fire on Fort Necessity. Washington ordered his troops to return fire, but they aimed too high, inflicting few casualties, and the swivel cannon fared no better. To add to the garrison’s troubles, heavy rain began to fall that afternoon, and Washington’s troops were unable to continue the firefight because their gunpowder was wet.
 
Louis Coulon de Villiers, who did not know when British reinforcements might arrive, sent an officer under a white flag to negotiate. Washington did not allow the Canadian officer into or near the fort, but sent two of his own men, including his translator Jacob Van Braam, to negotiate. As negotiations began, the Virginians, against Washington’s orders, broke into the fort’s liquor supply and got drunk.Coulon told Van Braam that all he wanted was the surrender of the garrison, and the Virginians could go back to Virginia. He warned, however, that if they did not surrender now, the Indians might storm the fort and scalp the entire garrison.
 
Van Braam brought this message to Washington, who agreed to these basic terms. One of Louis Coulon de Villiers’ aides then wrote down Coulon’s surrender terms and then gave them to Van Braam, who in turn gave them to Washington. Washington, who could not read French, had Van Braam translate it for him, and in the document it said that Jumonville had been “assassinated”. However, Van Braam may have skipped over this word; otherwise Washington would have likely sent it back to Coulon and asked that the word be removed. Both Washington and Mackay signed the surrender document.
 
Bron: en.wikipedia.org