Complex sentence: Through the warm months of 1813 and 1814, he spied on the British, attacked their supply boats, robbed mail couriers, burned ships, and participated in the battles of Sackets Harbor and Crysler's Farm.
Split into simpler sentences: Through the warm months of 1813 and 1814, he spied on the British. He participated in the battles of Sackets Harbor and Crysler's Farm.