The Merchant Marine Act of 1920 (P.L. 66-261), also known as the Jones Act, is a United States federal statute provided for the promotion and maintenance of the American merchant marine. The law regulates maritime commerce in U.S. waters and between U.S. ports.
In the case of the continental mainland, this act doesn't have visible repercussions, but for Hawaii, Alaska, and US territories the effects are catastrophic; increasing live cost around 50 percent in comparison to citizens that live in the mainland. For example, as commented on the Huffington post by Sen. Sam Slom, it costs about $790 to ship a 40-foot container from Los Angeles to Shanghai, but it costs $8,700 to ship the same container from Los Angeles to Honolulu.