Complex sentence: In World War I there was a great demand for manganese as a strengthening agent for steel, and the industry became a substantial employer in the village; over 113,000 tons of ore were extracted between 1840 and 1945, and in 1906 the industry employed 200 people.
Split into simpler sentences: In World War I there was a great demand for manganese as a strengthening agent for steel, and the industry became a substantial employer in the village. Over 113,000 tons of ore were extracted between 1840 and 1945, and in 1906 the industry employed 200 people.