Whistle-Stop Tour

Comes directly from railway practice. A train wouldn't normally stop at a small station unless someone needed to board or get off; if it was going to stop, the engineer sounded the whistle to alert the town. The term "whistle stop" for these minor railway halts was in use by the 1920s. It became a political phrase specifically through President Harry Truman's 1948 re-election campaign, when he travelled by train and made numerous short speeches from the observation platform at the back of the carriage in one small town after another, sometimes delivering up to eight speeches in a single day.