Theodore Roosevelt's blockade lesson from the War of 1812

Britain tightened its blockade after Napoleon's reverses freed resources for the war against the United States. By May 1813 it was complete from New York southward and later extended east, while Britain initially spared New England the same severity in hopes that local dissent would become revolt. Georgia retained limited trade through Spanish Florida, but elsewhere merchant shipping largely stopped and ships rotted in port. Privateers and a few regular cruisers could sometimes thread through the blockade and win prestige, yet they could not preserve normal commerce or prevent attacks along the seaboard. Roosevelt contrasts this weakness with Jefferson's failed attempt at peaceful economic coercion. His conclusion is that an ocean-facing state cannot substitute isolated tactical successes for the sea power needed to repel sustained pressure. That lesson helped shape later American naval doctrine.