The Embargo Act of 1808 prohibited domestic commerce to foreign flags, and this edict was renewed in the American Navigation Act of 1817.

It remained a firmly established doctrine of maritime policy until the Great War compelled its suspension as an emergency measure.

The theories of protection and free trade have been bitterly debated for generations, but in this instance the practice was eminently successful and the results were vastly impressive.

Deepwater shipping dwindled and died, but the increase in coastwise sailing was consistent.

It rose to five million tons early in this century and makes the United States still one of the foremost maritime powers in respect to saltwater activity.
To speak of this deep-water shipping as trade coastwise is misleading, in a way.