American shippers took advantage of the hostilities in Europe to absorb the carrying trade between Europe and the French and Spanish islands in the West Indies. By breaking the passage with a stop in a U.S. port, they evaded seizure under the British rule of 1756, which forbade to neutrals in wartime trade that was not allowed in peacetime. In 1805, however, in the Essex Case, a British court ruled that U.S. ships breaking passage at an American port did not circumvent the prohibitions set out in the rule of 1756. As a result the seizure of American ships by Great Britain increased. In 1805 Britain seized over 200 ships alone. Then Napoleon declared a blockade of England and also began to confiscate American ships.
The exchange between British ship “Leopard” and American frigate “Chesapeake” in 1807 prompted Jefferson to order all British ships out of American water and prohibited foreign ships from the American export trade. The effect of this self imposed embargo would have a disastrous effect on the American economy sending it into a depression in 1808. Napoleon took advantage of this flawed policy and claimed the right to attack American ships in any continental port because, by Jefferson’s own order they were illegal carriers and in violation of the embargo.
In 1809 Congress with President Madison’s approval replaced the embargo with the NON-Intercourse.