The term "whistle stop" comes from the days when trains were the primary mode of transportation. When a train would stop at a small town or village, the conductor would blow the whistle to signal the arrival of the train. The people of the town would then come out to meet the train and see who was on board. If there was a politician or other public figure on the train, they would often give a short speech or hold a meeting with the locals.
Whistle stop tours are a long-standing tradition in American politics. Some of the most famous whistle stop tours include the one conducted by President Harry Truman in 1948 and the one conducted by Senator John F. Kennedy in 1960. In recent years, whistle stop tours have become less common, as politicians are increasingly able to reach voters through social media and other electronic means. However, they can still be an effective way to connect with voters and generate media attention.