Eh...things would have been very different if the US had to remain inside roughly the same boundaries it had at the time of its founding, rather than having an entire continent to expand into.
France has been through multiple Republics but hasn't really had a huge civil war since the French revolution, and I don't think you can blame France for all the instability brought about by external aggression (Franco-Prussian War, WW1 & 2) notwithstanding France's own missteps. Again, the US is in the happy geographic position of only have 2 immediate neighbors, both of which are substantially weaker in military and economic terms and both of which it had already beaten in war.
I do think there is something worthwhile to the way the US Constitutional system operates, and that the difficulty of amending the Constitution has been a good thing overall. But to ascribe the countries' very different histories to legal structures alone without considering geopolitical and economic differences is a bit facile. One might as well argue that France had existed in approximately the same territory for nearly 2500 years while the US has only been in existence for about 1/10th of that time - it's approximately true but not really informative.
nitpick: the Canadians actually beat us in the war of 1812. Twice if you count the failure of Benedict Arnold's campaign. The real reason for the peace along our northern border was Britain's post-Munroe policy of trying to cultivate an alliance with us as a means first of securing free access to Latin American ports and later of having us to aid it in its traditional role of balancing against the prospect of a hegemony on the European mainland.
France has been through multiple Republics but hasn't really had a huge civil war since the French revolution, and I don't think you can blame France for all the instability brought about by external aggression (Franco-Prussian War, WW1 & 2) notwithstanding France's own missteps. Again, the US is in the happy geographic position of only have 2 immediate neighbors, both of which are substantially weaker in military and economic terms and both of which it had already beaten in war.
I do think there is something worthwhile to the way the US Constitutional system operates, and that the difficulty of amending the Constitution has been a good thing overall. But to ascribe the countries' very different histories to legal structures alone without considering geopolitical and economic differences is a bit facile. One might as well argue that France had existed in approximately the same territory for nearly 2500 years while the US has only been in existence for about 1/10th of that time - it's approximately true but not really informative.