Was the combat and warfare during the ACW unique to any warfare in Europe post Napoleon?

Maybe. I don't know the exact reflections in Europe about the American Civil War. But certainly some people in the Prussian General Staff thought about it.
A large and sparsely populated country with nearly no standing army before the conflict looks different to the 19. century european wars from a european perspective.
General Sheridan was an observer during the Franco Prussian War. His comment was he would be curious as to how the Germans and French would handle American conditions (bottomless roads, natural chokepoints)
 
Other conflicts to learn from are probably the many smaller colonial wars (about which I don't know enough to really comment)

Well, the British army of 1914 had a strong emphasis on teaching its troops fieldcraft and marksmanship skills, a direct result of their experience against the Boers. This emphasis stood them in good stead in the early months of WW1.

I guess Europeans thought the American Civil War lasting 4 years must have been an American phenomena then? Because WW1 was also expected to initially be a short war.

I don't know what, if anything, Europeans of the 1910s thought about the ACW, but the reason they expected WW1 to be short was because they were basically expecting it to follow the pattern of previous European wars, namely, "Both sides gather as many troops as possible and march against each other, you fight a big battle, and then either the loser sues for peace or the winner pushes onwards, keeping the loser off-balance and driving them back until they sue for peace." That's probably how the ACW would have gone if both sides had started off with big European-style armies, too: if the Confederates had been well-trained enough to keep their cohesion after Bull Run, they could have pushed onwards immediately, scattered the retreating Union Army, and attacked Washington before the Feds could get their defences in order.
 
I guess Europeans thought the American Civil War lasting 4 years must have been an American phenomena then? Because WW1 was also expected to initially be a short war.

Well the Third Carlist War went almost 4 years but that was largely a guerrilla fight as the Carlists quickly realised the Liberals (official name but they are Spanish so your mileage might vary) had a standing army and they had an untrained mob. So it may have been long seemed normal for internal conflicts to linger while 'civilised' conflicts between well organised armies were expected to be settled quickly with a 'decisive battle'.
 
Straying a little bit from the topic, does anyone have some resources or references on how the various powers organized themselves in the late Victorian era? I know how the US Army did things (poorly), and a bit about the Brits, but not much else.
 
Straying a little bit from the topic, does anyone have some resources or references on how the various powers organized themselves in the late Victorian era? I know how the US Army did things (poorly), and a bit about the Brits, but not much else.

Do you mean something like this?

Notes and Statistics of Organization, Armament and Military Progress of American and European Armies

It is not 100% accurate as it represents the best notions of US Army Intelligence for late 1895 (the pamphlet was published in 1896) but it is put together by professionals at the US War Department and does cover several European powers plus Columbia and Mexico.
 
Do you mean something like this?

Notes and Statistics of Organization, Armament and Military Progress of American and European Armies

It is not 100% accurate as it represents the best notions of US Army Intelligence for late 1895 (the pamphlet was published in 1896) but it is put together by professionals at the US War Department and does cover several European powers plus Columbia and Mexico.


Fabulous, thank you gents.
 
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