Complex sentence: In 1782, McGillivray became the principal chief of the Upper Creek towns after his predecessor, Chief Emistigo, died while leading a war-party to relieve the British garrison at Savannah, which was besieged by the Continental Army under General'Mad' Anthony Wayne.
Split into simpler sentences: In 1782, McGillivray became the principal chief of the Upper Creek towns. His predecessor, Chief Emistigo, died while leading a war-party to relieve the British garrison at Savannah, which was besieged by the Continental Army under General'Mad' Anthony Wayne.