The renewed fighting between France and the United Kingdom in 1803 heavily tested American neutrality. Indeed, the overall situation turned more difficult when the British navy under Lord Nelson managed to defeat the French fleet at the Battle of Trafalgar in 1805 and took control of the seas. American merchants had been deriving huge benefits from the war by simply shipping sugar and coffee brought from French as well as Spanish colonies in the Caribbean to Europe. The United Kingdom didn’t appreciate it because the prices it was getting for its West Indies products were going down. Taking into account that French ports visited by neutral American merchant ships (in order to preserve the French merchant marine from the UK) would have been unavailable to the United States in peacetime, and only French deliveries were allowed. The United Kingdom invoked the Rule of 1756, pointing out that such ports shouldn’t be available during war to neutral replacements. US traders got around the rule by simply taking French as well as Spanish products to American ports, unloading them, and after this reloading them for European ports as pure American exports.
By 1805, the United Kingdom had faced more than enough of such deceptions, and through a bunch of trade decrees started a blockade of French‐controlled European ports. The French and also the British ignored American neutrality claims and kept seizing American merchant ships. The UK resumed the policy of impressment, thus taking alleged UK navy deserters off American vessels and then returning them to British service. We should stress that the life of an American sailor appeared to be hard, though nothing like that in the British navy with its low pay and harsh discipline. A great number of British deserters had become American citizens, but it didn’t stop UK officials from impressing them, nor did the British hesitate in taking American-born citizens, who had an opportunity to prove their American birth. During the period 1807-1812, the Royal Navy impressed up to six thousand American seamen.
In June 1807, the UK warship Leopard attacked an American navy frigate, the Chesapeake and four alleged deserters were removed. Amid the public's cry for war against the UK, Jefferson decided to take advantage of economic pressure to resolve this crisis. For instance, in December 1807, the so-called Embargo Act was passed by Congress. The given measure stopped exports and also prohibited the departure of merchant ships for foreign ports.
The renewed fighting between France and the United Kingdom in 1803 heavily tested American neutrality. Indeed, the overall situation turned more difficult when the British navy under Lord Nelson managed to defeat the French fleet at the Battle of Trafalgar in 1805 and took control of the seas.