1920's was a great depression going on and everyone needed money then was ww1 and today we need money and jobs a war would keep people employed.
One of the main reason for this variety to be so wide is colonization. In the Caribbean there were mainly three types of colonies: English, French and Spanish. Also, on top of that, they brought slaves from Africa which help to add African culture to the mix, leading to a more profound exchange of cultures.
Taking that into account, it is normal that there is so much diversity. Traditional practices from every individual island mixed with the ones coming from their colonizers and their slaves, creating entirely different practices in every single island.
The Sherman Antitrust Act of 1890, The Clayton Act of 1914, The Federal Trade Commission Act of 1914, The Robinson-Patman Act of 1936, and The Hart-Scott-Rodino Antitrust Improvements Act of 1976. My source for this information was http://www.abc-amega.com/articles/commercial-law/u-s-antitrust-law hope this helps:)
