Oriskany Battlefield stood at the heart of the American Revolution in the Mohawk River Valley, which in 1777 again became a critical military corridor for moving men and materials. There British Loyalists with their Seneca and Mohawk sympathizers ambushed colonists and their Oneida allies, with each side determined to defend its values and way of life to the death. On August 6, the British campaign of 1777, a strategic effort to isolate New England from the rest of the colonies, began to fail. In that invasion of New York, General John Burgoyne was to move south through the Champlain Valley from Canada, while General Barry St.Leger was to move west up the St.Lawrence River to Fort Ontario at Oswego and then east along the Mohawk, and Clinton's army was to strike northward up the Hudson Valley from New York City so they could meet at Albany. Although Burgoyne enjoyed early success, St.Leger's 1,200-man army of British regulars, German mercenaries, and Loyalist divisions working with Native American allies stalled at Fort Stanwix, leaving Burgoyne increasingly isolated as he approached Albany before he surrendered his entire army at Saratoga on October 17, 1777.