Complex sentence: During the war, Father Rale was killed by the British at Norridgewock; the native population retreated from the Kennebec and Penobscot rivers to St. Francis and Becancour, Quebec, and New England took over much of the Maine territory.
Split into simpler sentences: During the war, Father Rale was killed by the British at Norridgewock. The Indian population retreated from the Kennebec and Penobscot rivers to St. Francis and Becancour, Quebec, and New England took over much of the Maine territory.