Complex sentence: During the late 19th and early 20th centuries, Kingston was an important Great Lakes port, transshipment point, and a centre for shipbuilding and locomotive manufacturing, including the Canadian Locomotive Company, at one time the largest locomotive works in the British Empire.
Split into simpler sentences: During the late 19th and early 20th centuries, Kingston was an important Great Lakes port, transshipment point, and a centre for shipbuilding and locomotive manufacturing. The Canadian Locomotive Company was at one time the largest locomotive works in the British Empire.