Final answer:
George Washington served as Commander-in-chief of the Continental Army during the American Revolution, appointed on June 15, 1775, and played a key role in leading the American forces to victory.
Step-by-step explanation:
During the American Revolution, George Washington's role was a) Commander-in-chief of the Continental Army. On June 15, 1775, he was appointed to this position and led the force until 1783. His leadership was instrumental in American victory, with notable successes such as the surprise attack on the Hessians at Trenton, New Jersey, and the strategic use of cannons to force the British evacuation from Boston. Washington's commitment to the revolutionary cause and his exemplary conduct as a military leader earned him the title "Father of our Country."