The document discusses several external events in the 19th and early 20th centuries that affected Singapore, including the Industrial Revolution, opening of the Suez Canal, World Wars I and II, and the Great Depression. The Industrial Revolution led to more ships visiting Singapore for trade. The opening of the Suez Canal significantly reduced travel time between Europe and Singapore, expanding trade. World War I caused temporary food shortages and a mutiny in Singapore was put down. The Great Depression negatively impacted Singapore through reduced demand for exports and widespread unemployment.