War of 1812
Impressment, trade, and naval actions

Britain was the largest trading partner of the United States, receiving 80 percent of American cotton and 50 percent of all other American exports. The British public and press resented the growing mercantile and commercial competition. Historian Reginald Horsman states that "a large section of influential British opinion thought that the United States presented a threat to British maritime supremacy".

During the Seven Years' War, Britain introduced rules governing trade with their enemies. The Rule of 1756, which the U.S. had temporarily agreed to when signing the Jay Treaty, stated that a neutral nation could not conduct trade with an enemy, if that trade was closed to them before hostilities had commenced. Since the beginning of Britain's war with France in 1793, the U.S. merchant marine had been making a fortune continuing trading with both nations, America's share of trans-Atlantic trade growing from 250 thousand tons in 1790 to 981 thousand tons in 1810, in the process.

Of particular concern to the British was the transport of goods from the French West Indies to France, something the U.S. would have been unable to do, due to French rules, during times of peace. The United States' view was that the treaty they had signed violated their right to trade with others, and in order to circumvent the Rule of 1756, American ships would stop at a neutral port to unload and reload their cargo before continuing to France. These actions were challenged in the Essex case of 1805.

With parts of the Jay Treaty due to expire in 1806, a new agreement was sought. The Monroe–Pinkney Treaty offered the U.S. preferential trading rights and would have settled most of its issues with Britain. However, the treaty did not moderate the Rule of 1756 and only offered to exercise "extreme caution" and "immediate and prompt redress" with regard to impressment of Americans. President Thomas Jefferson, who had specifically asked for these two points to be extirpated, refused to put the treaty before the Senate.

In 1806, Napoleon's Berlin Decree declared a blockade of the British Isles, forbade neutral vessels harbour in British ports, and declared all British made goods carried on neutral ships lawful prizes of war. The British responded in 1807 with Orders in Council which similarly forbade any shipping to France. By 1807, when Napoleon introduced his Milan Decree, declaring all ships touching at British ports to be legitimate prizes of war, it had become almost impossible for the U.S. to remain neutral. Between 1804 and 1807, 731 American ships were seized by Britain or France for violation of one of the blockades, roughly two thirds by Britain. Since the Jay Treaty, France had also adopted an aggressive attitude to American neutrality.

While Britain, through a process known as pre-emption, compensated American ship owners for their losses, France did not. French frigates burned American grain ships heading for Britain and treated American sailors as prisoners of war. US–French relations had soured so much that by 1812, Madison was also considering war with France.

As a result of these increasing trade volumes during the Napoleonic Wars the United States Merchant Marine became the world's largest neutral shipping fleet. Between 1802 and 1810, it nearly doubled, which meant that there were insufficient numbers of experienced sailors in the United States to man it. To overcome this shortfall, British seamen were recruited, who were attracted by the better pay and conditions. It was estimated that 30% (23,000) of the 70,000 men employed on American ships were British. During the Napoleonic Wars, the British Royal Navy expanded to 600 ships, requiring 140,000 sailors.

The Royal Navy could man its ships with volunteers in peacetime, but in wartime, competing with merchant shipping and privateers for the pool of experienced sailors, it turned to impressment from ashore and at sea. Since 1795 the Quota System had been in use to feed men to the navy but it was not alone sufficient. Though most saw it as necessary, the practice of impressment was detested by most Britons. It was illegal under British law to impress foreign sailors, but it was the accepted practice of the era for nations to retrieve seamen of their own nationality from foreign navies during times of war. However, in the nineteen years Britain was at war with France prior to the war of 1812 some ten thousand American citizens were impressed into the British navy.

The American ambassador in London, James Monroe, under President Jefferson, protested to the British Foreign Office that more than fifteen thousand Americans had been impressed into the Royal Navy since March 1803. When asked for a list however, the Madison administration was only able to produce one based on hearsay containing 6,257 names, many of which were duplicated. The list also included some who had legitimately volunteered to serve. By 1804, the incidents of impressment of Americans had sharply increased. Underlying the dispute was the issue that Britain and the United States viewed nationality differently. The United States believed that British seamen, including naval deserters, had a right to become American citizens. In reality few actually went through the formal process.

Regardless Britain did not recognize a right for a British subject to relinquish his citizenship and become a citizen of another country. The Royal Navy therefore considered any American citizen subject to impressment if he was born British. American reluctance to issue formal naturalization papers and the widespread use of unofficial or forged identity or protection papers among sailors made it difficult for the Royal Navy to tell native born-Americans from naturalized-Americans and even non-Americans, and led it to impress some American sailors who had never been British.

Though Britain was willing to release from service anyone who could establish their American citizenship, the process often took years while the men in question remained impressed in the British Navy. However, from 1793 to 1812 up to 15,000 Americans had been impressed while many appeals for release were simply ignored or dismissed for other reasons. There were also cases when the United States Navy also impressed British sailors. Once impressed, any seaman, regardless of citizenship, could accept a recruitment bounty and was then no longer considered impressed but a "volunteer", further complicating matters.

American anger with Britain grew when Royal Navy frigates were stationed just outside American harbours in view of American shores to search ships for goods bound to France and impress men within the United States territorial waters. Well-publicized events outraged the American public such as the Leander affair and the Chesapeake – Leopard affair.

The British public were outraged by the Little Belt affair in which the larger USS President in search of HMS Guerriere instead clashed with a small British sloop, resulting in the deaths of 11 British sailors. While both sides claimed the other fired first, the British public particularly blamed the United States for attacking a smaller vessel, with calls in some newspapers for revenge. President had sighted and chased HMS Little Belt trying to determine her identity throughout the afternoon.

The first shot took place after an exchange of hails had still failed to identify either ship to the other in the growing dusk. After 45 minutes of battle, taking place in darkness, Little Belt had received much damage, with several holes to her hull near the water-line and her rigging "cut to pieces". President ' s Captain Rodgers claimed Little Belt had fired first; but he did not ascertain her size or country of origin until dawn. After sending over a boat, Rodgers expressed regret and apologized for the 'unfortunate affair'.

Little Belt ' s Captain Bingham claimed the opposite: President had fired first and had been manoeuvering in such a way as to make him think she was planning an attack. Historian Jonathon Hooks echoes the view of Alfred T. Mahan and several other historians, that it is impossible to determine who fired the first shot. Both sides held inquiries which upheld their captain's actions and version of events. Meanwhile, the American public regarded the incident as just retribution for the Chesapeake–Leopard affair and were encouraged by their victory over the Royal Navy, while the British regarded it as unprovoked aggression.
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