It's absolutely insane we don't do a shit load more shipping in this amazing river system. Thanks, Jones Act.

The tldr is that to go directly between two ports in the United States, a ship must be American built and flying American colors. The law is the result of the shipping industry's lobbying efforts 100 years ago. Until that point, American shipping had been considered the best for several decades, and they'd rather have Uncle Sam protect them instead of doing anything to be more attractive. This is why if you get on a cruise ship, you always visit a foreign port. You can't sail directly between Houston and New York. It also means that cargo sent within the United States can't go by water. All cargo moving domestically moves by road, rail, or air.