Complex sentence: In 1723, the village of Canso, Nova Scotia was raided again by the Mi'kmaqs, who killed five fishermen, so the New Englanders built a 12-gun blockhouse to guard the village and fishery.
Split into simpler sentences: In 1723, the village of Canso, Nova Scotia was raided again by the Mi'kmaq, who killed five fishermen. In this same year, the New Englanders built a twelve-gun blockhouse to guard the village and fishery.