How does an ample presence of navigable canals, rivers, and coastal waterways help a country's economy?

Question

I read it does help.

I am just trying to understand a country's development better.

(If you need an example, then be it the United States of America)

Answer 1

Transporting by water  is cheaper than other methods .But it is bit slow.

Rail is also better as less friction on the road/tyres.

IN USA automible lobby controls what you want to use!

Answer 2

prior to 1920 or so, it was very important, as it was necessary for the transportation of goods.

After that with the development of the truck and highway, it became less important, as a trucking system will do the same thing.