Many Americans had more money and more leisure time.
Explanation:
During the period of 1920s, which was widely referred to as Jazz Age. This period in America was characterized by the economic boom which led to a better standard of living among the citizens and consequently the produces seek to meet the increased demands of consumers in terms products and services that they were considered as want rather than need.
Hence, it can be concluded that the cause of consumerism in the 1920s, was as a result of "Many Americans had more money and more leisure time."
It did not come to a complete halt but it did slow down a little. This is because of the Stono Rebellion which took place from 1739-1750. The slave trade came to a halt during the Revolutionary War