Seaplanes and airplanes deliver air mail in 1920s

The transcript discusses the early days of airmail service, highlighting its importance and the advancements made by 1921. It notes the remarkable achievement of delivering a letter from New York City to San Francisco in just over 33 hours, marking the reality of transcontinental airmail delivery.

What does the phrase 'bounding main event' refer to in the context of airmail service?

Describe the significance of the early days of airmail service.