Complex sentence: John and his wife Annie arrived in Puget Sound circa 1889 from Canada, intending to establish themselves in the shingle-making trade, eventually opening their own shingle mill on the northern shore of Lake Washington on land leased from Watson Squire.
Split into simpler sentences: John and his wife Annie arrived in Puget Sound circa 1889 from Canada, intending to establish themselves in the shingle-making trade. They opened a shingle mill on the northern shore of Lake Washington on land leased from Watson Squire.