Complex sentence: With the coming of the war, the same harbor facilities which made it a seaport, made it a home base for American privateers who would attack and seize British ships and take their captured prizes into Chestnut Neck.
Split into simpler sentences: With the coming of the war, the same harbor facilities were used by American privateers as a home base. They would attack and seize British ships and take their captured prizes into Chestnut Neck.