[Don Corleone]

Both Churchill and Eisenhower gave much credit to the merchant marine, both US and British for winning the war in Europe.

And now...the Merchant Marine in the USA is for all practical purposes non-existent.

[Maine Mariner]

Yes, it is unfortunate that the US merchant marine is
non-existent. The military sea-lift command operates a good size fleet and of course Jones Act ships.

A combination of many factors-government tax policies and regulations, labor unions, hidebound management that depended on too much government subsidies and not enough
innovation and so forth.