Explain how the speculative boom of the 1920s came about

The economic boom in the 1920's is all about the start and wide use of technology and construction of infrastructures to aid man on industrial needs. 
This was a significant turning point in the economy that opened faster means of transportation and communication. 

Trains, cars, and other vehicles were popularly used during those days. It made product distribution and raw material supply be on time. The working force can do and finish their jobs earlier.  To further maximize productivity, more roads were done for smoother and faster travel.

Electricity was widely distributed and made accessible to all people. It made electronic utilities like radios and telephones work for efficient communication. 

All the necessary economic improvements were laid out the 1920's to  

The have over 100 billion people in america