The Embargo Act of 1807 imposed a general embargo that made any and all exports from the United States illegal. It was sponsored by President Thomas Jefferson and enacted by Congress. The goal was to force Britain and France to respect American rights during the Napoleonic Wars. They were engaged in a major war; the U.S. wanted to remain neutral and trade with both sides, but neither side wanted the other to have the American supplies. The American goal was to use economic coercion to avoid war and to punish Britain. The policy was highly unpopular with shipping interests, and historians have judged it a failure. It was repealed as Jefferson left office in 1809. The embargo was imposed in response to violations of U.S. neutrality, in which American merchantmen and their cargo were seized as contraband of war by the European navies. The British Royal Navy, in particular, resorted to impressment, forcing 10,000 seamen with American papers into service on its warships. Britain and France, engaged in a struggle for control of Europe, considered the plunder of U.S. shipping to be incidental to war and indeed necessary for their survival. Americans saw the Chesapeake-Leopard Affair as a particularly egregious example of a British violation of American neutrality. Many Americans wanted war but Jefferson wanted to use economic coercion instead.