What if tensions between Britain and the US had been resolved diplomatically, and there had been no war of 1812?
 
Much less prominence for Andrew Jackson. Maybe Clay in 1824?

Earlier change would possibly be no Monroe administration. Monroe became more of an icon during the war because of his defense of Washington, and also being both Secretary of State and War. Granted he was Secretary of State since 1811, but what he did during the war is what made him more so available a choice to succeed Madison.
 
Much less prominence for Andrew Jackson. Maybe Clay in 1824?

IMO it's more likely that Adams wins the popular vote, but the electoral college is still deadlocked in a three way race. So Clay still swings his support to Adams in exchange for the Sec State position. Without Jackson, there are no charges of a "corrupt bargain" and Adams might go on to be a two term President. But by the 1830s some sort of second party system is going to come about eventually. If not lead by Jackson, it would be lead by Van Buren.
 
Well how does it get resolved? 1812 was pretty important for ultimately deciding what the border would be

I remember a David T post where he argued that the 49th parallel had been used in a prior border survey in 1807, so it would probably remain a rule of thumb even without the war. That's what I went with in my own timeline that averts 1812, in any event.

Other than that, I had Crawford upset Monroe in 1816, and without New Orleans, Jackson got upstaged by a living Zebulon Pike, and Clay squeaked through in 1824.
 
One amusing consequence is the US might actually ''conquer' Canada. The war was the cause of a wave of Canadian patriotism. Without that, regular interactions, commercial and personal, would lead to closer relations. Patriotism towards BRITAIN was significant, but a little distant. The was little patriotism towards the Family Compact, the small clique who ran Canada.

So, without the war, practicality, and a desire for a political voice might well have led Ontario, at least, to join the US. With the war (OTL), that possibility disappeared.

So the War of 1812 may have been the best thing to happen, for Canada.
 
The War of 1812 had a sobering impact on US estimations of British military power and led to major military reforms. Without it, I can see a cocky US getting into a war with the UK over the Maine or Oregon border and then losing badly. Britain would only be a stronger industrial power and not distracted by European enemies if the second Anglo-American war took place in the 1820s or 30s.
 
the war was vastly important in establishing the border, confirming the US purchase of the LA territory, and being the last real effort of 'conquer Canada'. It also started showing the first cracks in the US regions; the south and New England opposed the invasion of Canada. Without an actual war, getting a consensus to conquer Canada later on might be difficult. It really comes down to if the US and UK can come to a peaceful settlement of the border; without knowing just who the President will be, it's hard to say. If it happens, then the US is going to be far more interested in it's coast to coast Manifest Destiny (something the whole nation got behind) rather than conquering Canada (which exposes sharp regional differences)…
 
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