As Louisiana merged fitfully into the United States, tensions between the newly enlarged nation and the powers of Europe were rising to a head. 1803 marked the end of the Peace of Amiens, and the resumption of the battle royale between Napoleonic France and the major powers of Europe. Under the energetic leadership of Prime Minister William Pitt the Younger, the British had corralled a new alliance that included Sweden, Russia, and the soon to be extinct Holy Roman Empire into the Third Coalition. While their allies repeatedly confronted and lost to Napoleon’s forces on land, the British concentrated their efforts into a large scale naval blockade with the intention of strangling the economic lifeblood of France and preventing any possible invasion of the British islands themselves.
Needless to say, the British took a dim view of neutral commerce on the high seas, of the kind the United States and other bystanders were keen to peddle. To the British navy, any power that was actively trading with the French were de facto aiding and abetting Napoleon, and they maintained a standing policy of treating any goods bound for French ports as contraband. Any ships or nations that tried to circumvent this standing order risked bringing down Thor’s hammer on themselves. Already in 1801, one earlier attempt by the northern European nations to found a “League of Armed Neutrality” had prompted no less a figure than Admiral Nelson to obliterate the Danish fleet at the Battle of Copenhagen.
From 1803 onwards the British were regularly stopping American ships on the high seas, or in neutral or British ports, and seizing what they considered “contraband”. While this was a French habit as well, only the British happened to view some of America’s sailors in the category of seizable goods. Life in the British Navy was not a pleasant one, and finding the men needed to crew the world’s greatest navy was always a challenge even when they weren’t engaged in a full scale war. In the homelands roving press gangs would pick up likely targets, or trick them into taking the King’s coin after a night of heavy drinking. Many a sailor’s career began with a thumping hangover and a day in the brig. Unfortunately for the young United States, British law considered anyone born in Britain to still be British, regardless of which nation they now resided in. Combined with their already dim view of the United States in general, and knowledge that the Americans were on some level actually encouraging sailors to desert, the British navy would regularly stop ships and seize men they considered “deserters” whether they were or not. By some estimates, this amounted to almost a thousand men annually from 1803-1812, a horrible and arbitrary fate that left the United States feeling powerless to protect its citizens.
Interestingly, the most notorious of these sailor seizures actually centered around a British sailor who had actually jumped ships in the United States. In 1807, the British found themselves blockading two French warships in the Chesapeake Bay. Situations like this one were fairly common, as the British were forever engaged in a game of whack-a mole with French privateers on the high seas. As the English waited for the French to make a break for it, they noticed that some of their ships were hemorrhaging men. British native Jenkin Radford was one of the men to make a break for it, and he found a new place within the United States Navy. Now safely aboard the USS Chesapeake, Radford made the mistake of broadcasting his success, loudly, at the British officers on shore leave. It didn’t take word long to leak back, and the HMS Leopard was dispatched to reclaim the errant sailor.
The next time the USS Chesapeake sailed into international waters, she was followed by the Leopard. It’s very hard to shadow a wooden ship subtly, and it didn’t take the Chesapeake’s captain Barron to notice his pursuer. After several minutes of shouted and confused conversation between the two captains, Barron agreed to check his crew for deserters. As Radford had signed up under a pseudonym, he slipped the net, and the other three the Leopard were after were considered American in the eyes of the Chesapeake. After Barron refused to heave to, the Leopard pounced. Before the American ship could even remove the covers from her guns, the Leopard fired, and killing three and wounding another 18 sailors. Wounded himself Barron struck colors and gave up. The British boarded, grabbed the offending Radford, who was later hanged, and the three Americans they considered deserters due to their record of service in the Royal Navy. The problem was that all three other men were American by birth. Laughing at the comical series of events that led to this misunderstanding, the British naturally returned the men to their home country. This took five years, and one died in a British prison waiting. Needless to say the incident was a nasty shock to the United States, and left many Americans clamoring for a forceful response.
To his credit, then President Thomas Jefferson was extremely wary of swinging back at the British. Francophile though he was, Jefferson had done his best to keep his diplomatic options open and had even flirted with an alliance with Britain as a potential stick during the Louisiana Purchase negotiations. It also wasn’t like he had given himself much of a choice though, Jefferson had drastically scaled down the size of the standing army and there was no chance of the American navy standing up to even a modest British presence. Instead, Jefferson decided to avoid the strangling of his international trade by hauling it out behind the shed and killing it himself. The Embargo Act of 1807 was a ham fisted attempt to sever all trade with Britain and France, until they agreed to respect that “contraband is anything that can help each nation, or none of it is”.
While such an economic shot across the bow might have more pull today, it was a grave overstatement of the United States’ weight at the time. Both France and Britain found other markets, and all of New England took a financial nosedive as a result. Even as Jefferson and his successor James Madison refined and tweaked the Embargo Act and subsequent sanction themed bills, none of them produced any kind of contrition from the British. Frustrated and powered by a feeling of national impotence, the maritime raids became a powerful call to arms for the fledgling American War hawks.
 Which is really to say Austria, as the Holy Roman Emperor was effectively a title on paper by this point. The Prussians, as the other major German power, would get pulled into the sequel known as the War of the Fourth Coalition: Berlin Drift.
 This was a real possibility, and certainly contributed to the British siege mentality. Napoleon actually spent the majority of the Louisiana funds on preparations for a full scale assault, but the 1804 naval loss at Trafalgar put paid to this ambition.
 Ironically, the notion of a third league featuring Britain and France was floated during the American Civil War as a way of overcoming the U.S. blockade of the rebel states.
 The Chesapeake would have an equally bad time of it during the War of 1812 proper. Losing a ship to ship battle to a British vessel, it was captured, and eventually dismantled and turned into the Chesapeake Mill in Britain. Barron himself was found at fault for the incident, and so bristled at the stain on his record that he shot and killed the head government investigator in a duel years later.
 Twamley, Z. 2012. The War of 1812. When Diplomacy Fails Podcast.