How did that Puerto Rican rum or Louisiana crawfish end up in your local grocery store? The answer may be the old-fashioned way – on ships. But that’s not the only thing that’s old-fashioned about how those and other goods often get from point A to point B.

A 1920s-era law known as the Jones Act governs how American goods are shipped between two domestic ports. This law mandates that all commercial shipments between American ports be carried by American-made ships, staffed by a majority of American sailors and repaired by American crews.