Okay, my previous post was intended as a joke. The fact that it was apparently taken seriously is frankly a little disturbing to me...
If you think capitalisim is about the concentration of industry in a particular geographic area, you need to study some more economics (unless you're at Brown or somepace with a Marxist economics department...)
The expansion of an economy by exporting finished goods to distant markets, (and in turn taking the raw materials from those distant lands) is mercantilism, which is a pre-cursor to capitalism, but with markets that are less than open.
Lenin's notion of "exporting capital" is wide of the mark. Marxism is mostly normative theory about what should be the proper relationship between labor and capital...and generally demonstrates a poor understanding of capital. It's propaganda for the masses, to justify the concentration of power in a communist party. Redistribution of wealth was the justification given to the masses, but they were left with a government that was not less authoritarian (and arguably no more efficient) than what they had under the Czars.
I haven't read Hobson's view of imperialism, but unless he was quoted out of context, it's an awfully narrow view.
Three conditions must be in place before a capitalist imperialist war takes place. 1)underconsumption by workers. 2)overproduction of goods. 3)oversavings by the upper classes.
As with most propaganda, the world-view expressed in the above quote is way over-simplified. This is not sound economic theory, this is communist party doctrine. Nothing more.
Again, your application of Marx and Lenin to the American Civil War is an out-of-context, force-fit.
If you want to continue asserting that it was a capitalist-imperialist war on the part of the North, then please explain to me why the South fired the first shots? The north already HAD access to southern markets and goods. And it wasn't about access to cheap southern slave labor either. It would have been much easier for them to have simply instituted slavery (or bought slaves and kept them indebted for life for their "freedom") than to fight a war.
And please don't asser that it was the south that was the imperialist. They already HAD markets (Europe), and after all, they fought to separate themselves from the north, not to gain access to it.