The main causes cited by the United States in declaring war in 1812 were that Britain had violated American neutrality and territorial waters, blockaded American ports to ships from neutral countries and incited the Indians around Lake Michigan to resist white settlement.

To Canadians, however, it was nothing more that a blatant attempt by the Americans to take possession of the remaining British colonies in North America.

As well, Napoleon needed trade with the Americans to continue his war of conquest in Europe. The American merchants were finding it very profitable, selling goods and supplies to the French. The Royal Navy, however, was taking a dim view of the merchant ships that were suspected of transporting cargoes to France. The blockade was not against the United States, but against France. The only way to enforce a blockade at this time, was close on shore, near harbours and points of entry. Remember, radar is a modern invention, and ships could only cover an area that could be seen by their own lookouts. As well, the there was the problem of deserters.

Desertion was extremely high. It was impossible to leave a ship at sea, but when in harbour, many men "jumped ship." The opportunity best presented it's self in North America and the Caribbean. All a pressed man had to do was disappear and make his way to any United States government office or official.
Once there, he simply declared himself to be an American Citizen, swore an oath of allegiance, and was issued a certificate of citizenship. He did not even have to prove who he was. Most men gave false names and pasts. This did not matter to the US, though, as the country was young, and modern immigration policy had not yet been established. Anyone who asked, could become an American citizen. ^(*)
It was simply a matter of time before these men, sailors by trade, found their way onto US flagged merchant ships. Many of these ships were stopped by the RN, and searched, as part of the blockade against France.
When deserters where discovered amongst the crew, they were immediately arrested. Desertion from the RN was not taken lightly, and any Captain of any ship had the right to hang a man for that crime. Not all were hung, though. Many were given sentences of death, but not executed. They were simply put to work as crewmen again. Experienced sailors were in short supply, and few Captains were foolish enough to waste a valuable resource. When a the ship approached land, the convicted men would be chained, preventing them from jumping into the water, in an effort to swim ashore.

Needless to say, it all made good press for the lobbyist in both France and the United States, to encourage public support for war with Britain. From the British view point, the Royal Navy was only exercising it's right to arrest deserters. As far as the RN was concerned, these men were subject to HM King George, and members of the Royal Navy. The official response from the US government, however, could only be that they were United States Citizens.
All of this was further complicated by the "Golden Triangle" and the "Official" British stand on slavery.
 
 

 (*) All of this came squarely at Thomas Jefferson and James Madison, who had strongly opposed the Alien and Sedition Acts by the US Congress. These would have required 14 years residency for anyone applying for US citizenship. In an effort to create a more open government, they had provided the method these men needed to become Americans.

Map courtesy of Ontario Ministry of Culture and Tourism.
Canada and North Eastern United States, circa 1812

The NWC is the most daring. It consists of a group of Scots who have joined several small companies into one large one, in an effort to take on the monopoly giant, HBC.
Both the HBC and the AFC practised the "here we are" method of trade with the natives. They would travel as far as was practicable, using their access, and set up shop for trade. Natives who wanted goods could then come to them, either on the banks of the Mississippi or the Churchill rivers. The NWC went farther.
The NWC established permanent trade posts in the interior, that remained all year round. The natives no longer had to travel long distances, often through rival tribes, to trade for pots, knives, axes and guns. They were all over the interior of North America, as far north as the Arctic ocean, as far west as the Pacific ocean, and as far south as Mexico. The largest of all was in the Athabasca district, near the Arctic Ocean. All of these trade posts focused on the central inland headquarters, at the head of the Great Lakes.

The Treaty of Paris, 1783, changed all of that. The interior was divided between the United States and Great Britain. The NWC found it's inland headquarters, located at Grand Portage, in US territory. They were forced to move, about 40 miles north. This cost the NWC the use of the Grand Portage. It was the fastest and easiest route into the inland waterway from the Great Lakes. It also forced the construction costs of a new fort, at the mouth of the Kaministqua River. It was this move, or pay double taxes, to both the US and the British governments. The partners chose to move, but they refused to give up trading in the US owned part of the interior.

They knew that white settlers would bring modern farming, schools and churches into native life. As soon as the natives found that they could earn an easier living as farmers, than as fur trappers, they would quit hunting for furs. With schools would come a better understanding of European economics by the natives, and therefore, lower profits for the companies. With churches and missionaries, would come a loss of traditional native practices, which would again contribute to the decline of the hunter-gatherer society, that the fur trade depended on.

 The native people were caught in a struggle that change their culture forever.

Tribes were already showing the effects of European technology. After the introduction of communicable diseases by the Spanish in the 15th and 16th century, they were very slow to recover.

New trade goods from the British and French during the 18th century, increased the prosperity of the tribes beyond their imagination. Steel axes, iron pots, and reliable firearms made feeding your family much easier than before. The native population was on the rise.
 
 

Everyone is competing against every one else for something, and trying to play off the other parties against each other.

The fur traders are accusing each other of piracy, and demanding warrants of arrest and punishment for those who they accuse.
The NWC is in a bidding war with the HBC for trade goods in England. They are expanding around the globe, to offer the greatest selection of luxuries to Britain, in exchange for mass produced goods to ship to America.
The AFC is feeling the pinch because they cannot buy competitively in Europe. Britain is in the Industrial Revolution, and manufacturing, there, has outpaced everywhere else.

The fur traders are stirring up the natives to resist the settlers. The settlers are blaming their troubles on every one else.

The natives want to trade with the NWC because the prices are better, but the American government is telling them they can not.
 
 

He can also try to control settlement in the interior, by having himself appointed as it's governor. In fact, he never counts on what really happens.

The war in the interior will become one of looting and raiding. There are no military targets in the interior, with the exception the American forts at Makinac, Dearborn and Prairie du Chien. That leaves only the settlers' homesteads, fur posts and native villages to fight over.

This will establish the tone of American expansion into the interior for the next century.

 In the end, the natives are the biggest losers. They cannot stop the tide of settlement, or the influence of European culture and economics.
They side with the British, who win the war in the interior, and lose the peace at the treaty table. 

We have three main groups. The Americans in New England, the Canadians in Lower Canada, who are Royalist French by heritage, and the United Empire Loyalists in Upper Canada, who are a mixture of British, British Allied Six Nations Tribes, and American colonials who chose Britain over the US during the revolution.
 
 

On the whole, though, most simply believed what they were told about the British atrocities in the interior and on the high seas, and felt they were doing their patriotic duty.

Only the NWC is able to save the interior and northern territories, by maintaining a supply route via the French River to Lake Huron.

But the British lose control over what is now South Western Ontario. Early British victories at Detroit and Mackinac are rendered useless. The focus in Upper Canada is centred on the Niagara occupation.

It becomes a bitter war, comparable to the Peninsula Campaign in Spain. The US Army concentrates there, seeing it as it's best hope for success, only to be caught in a guerrilla campaign, fought by Militia and Mohawks.

Looting and brutality bring retaliation by the Militia, only to bring more brutality from the American soldiers.
The Niagara Occupation is a thing most Americans of the time are ashamed of, and much of it is omitted from official records by popular consent.

 John Astor gets some of his wishes, and some of his worst fears.
The British seize control of the upper Mississippi water way. For three years he is cut off from his fur trade.
The NWC and the HBC are both on the brink of closing, after the war. Eventually, they will merge, but not willingly.
The American Fur Company, however, never does recover. By 1834, John Astor is out of the fur trading business, and into real-estate.

 The American army eventually withdrew from Niagara, due to lack of food and supplies. The Canadian Militia has worn them down.
The only drawn out battle is the siege of Fort Erie. The British suffer huge casualties, and never successfully capture the fort. Only the threat of starvation makes the Americans leave.
The worst defeat is the burning of Washington. The American public loses all support for the war, after that.
Their only decisive land victory comes too late, at New Orleans, in January of 1815. The Battle however is fought after the official treaty is signed in Paris. News is too slow in reaching opposing armies, to tell them it is over.
By the end of the century, many American children have never heard of the War of 1812. By the 1960's, it is reduced to a folk song by Johnny Horton, based on a fanciful "Anti-British" movie made by Errol Flynn about Jean Laffite, a pirate.

If there was a winner, it was Canada.

Out of the Niagara Campaign, Canada discovered it's first National Hero, Isaac Brock, who died at the Battle of Queenstown Heights.
Brock's' Monument stands today, near Niagara Falls, Ontario. It was noted by the Prince of Wales, on his visit to Canada in 1860, that it was larger, and more magnificent than Nelsons Column in London.
With the loss of Brock's leadership in battle, the Canadians and UEL were left in the hands of generals who Wellington rejected from his staff in Europe.
The war set in motion the desire to establish a national identity for Canadians. It eventually leads to the Confederation of British North America, and the establishment of a new country, the Dominion of Canada.
It will be 70 years before Canadians feel at ease with their neighbours to the south. Upper Canada's capitol is moved from Kingston, to Ottawa, farther inland, away from the New York border.
It is replaced by a massive fortress, at Fort Henry, second only to La Citadel, in Quebec.
Both strongholds are connected by a chain of Martello Towers, and a semaphore telegraph. Canada will not be caught again.

Runcies Company of Coloured Men was formed during the War of 1812.
It was led by Captain Runcie, a white officer. He recruited run away black slaves.
These men had the most to loose, if the Americans succeeded in taking Canada. They were a credit to the Militia of Upper Canada. They fought bravely, and without care for themselves.
They were commended as a unit, for their valour, at the Battle of Queenstown Heights.

One of the objectives of the Niagara Occupation was to shut down the Underground Railroad, that helped escaped slaves into British territory.
In that same battle, an American officer named Winfield Scott was taken prisoner. Scott would eventually lead the Union army against the Confederacy, to help free black slaves, who he had once tried to re-capture.