Great questions 'berto, and I'll do my best to address 'em.

It may well be that in other parts of the world our civil war is regarded with less impact or importance than many here assign it, and understandably so, since it was "our" war and not your countrys or anyone elses.

Here however it's impacts were huge, both socially as well as in terms of blood and treasure. As a means of intensity and ferocity of the war itself, there were numerous single battles where the number of dead outpaced the number of soldiers killed in the entire Vietnamese action and indeed many multiples of the dead from our recent actions in Iran and Afganistan (<-note the term action instead of war regarding these as they were never declared as wars by any but those in total denial of what constitutionally enacted wars entail, but I digress).

In fact, only after the actions in Viet Nam did the number of American troops killed in all declared and undeclared wars reach the number lost in the civil war alone, which was over 500,000.

The basis for the war itself is commonly and fallaciously understood to be over slavery, as you mentioned, yet this was not the primary driver of the secession by the southern states and the eventual formation of the Confederate States of America.

Though such data is overlooked or swept under the rug in discussions of the war, at the time of the souths secession, slavery was legal in the US, though support for it had waned significantly over time, most especially in the northern states. Another overlooked idea is that fewer than 30% of all southerners were themselves slave owners. With these 2 examples alone it's quite a stretch to envision or equate slavery as the heart of the civil war.

So what did lie at the heart of the states secession?

Central to much of it was the concept of states rights under the Constitution, with the core issue in this debate revolving primarily in regards to slavery.

From 1800 to the civil wars onset there had been ongoing western expansion with the addition of many new territories and states and those in the north opposed to the idea of slavery, which again was still legal, lobbied for the practice of slavery to be outlawed in these areas. This lead many southerners to feel as if this was also a move to keep them from being included in this westward expansion since if they were slave owners they would not be allowed the same rights in the new territories as they held in their home states.

Another looming issue that dominated the politics of the south was a series of tariffs federally enacted which disproportionately effected the southern states, which coupled with an economic collapse of that time provided a double whammy effect to the economy in the south.

Though it wasn't an actual cause of the civil war or secession by the southern states, there was also a huge and undeniable social divide between the north and south. While the northern states had agricultural concerns, most of what brought on expansion and growth in the north was industry and manufacturing, while the south was mostly an agrarian economy with the bulk of their industry having been situated along the coastal areas to improve trade opportunities for their manufactured goods.

Prior to Lincolns election as president there had been a redistricting apportionment of the electoral college votes that by virtue of the more concentrated population in the north had essentially given the smaller land area of the northern states a disproportionate amount of political power over the larger, but less populated southern states. This lead many in the south who already saw northern states ideologies as counter to southern states needs to feel this was now being further pushed upon them as their legal representation in congress was also effectively being undermined as well, leaving then little course for legislative redress.

Kind of the straw that broke the camels back was when Lincoln was elected president even though he had failed to even secure enough backing to have been included on the ballot in 7 of the southern states. This lead to a now solid feeling in the southern states that their political will had been totally undermined and only further entrenched in the minds of most southerners that their secession had indeed been justified.

You asked what lead Confederate soldiers to fight against their fellow Americans and that's a REALLY great question, most especially in a war that literally often pitted friends and family members against one another in mortal combat.

The overwhelming issues of social divide, disproportionate taxational impacts and elective under representation lead to a very similar sentiment in the southern states as what the American colonies had felt in the revolutionary war, which was further compounded by Lincolns decisions to selectively suspend the writ of habeas corpus with a pointed intention of aiming this again very pointedly towards the southern interests, or any support of those interests.

The southern states had decided, as had the original colonies, that their needs were not being met by the US government and that their way of life and society were under attack by an overbearing system of government. Using the rights enumerated to the states they seceded from the union and the rest is history.

One last item certainly worth mentioning here however is that the confederate troops were fighting for the freedom from governmental oppression and indeed for the freedoms they envisioned the US Constitution had entitled them to, and to which they felt deprived of, essentially aligning them with various other "freedom fighters" before and since. This gave them a particularly powerful resolve and emotional advantage in their struggle, something many historians and northern military sources would note as an overwhelming tenacity by the confederate troops even when faced with overwhelming troop strengths and weaponry.

The union soldiers however were fighting for their governments policies while also fueled by propaganda and a sense of empowered moral righteousness stemming from that propaganda that they were fighting to free the slaves from their oppression (<-sounds very similar to many claims since that time made by other US war mongerers dudn it?) Secondly, many of the troops swelling the ranks of the union army were relative newcomers to America who had no particular dog in the fight, yet were granted citizenry, cash bonuses and a way to support themselves in their new country, which does not equate to the same level of resolve the confederate troops had comparatively.

This was also another fundamental difference in how both armies individually viewed the conflict.

Recent events in the US leave many of us feeling as if secession again might be the only answer to escape the nonsensical governmental interventions, police state tactics and social divide differences that exist today between the northern and southern societies.

And .... I can damned well betcha if it comes to that THIS Texan will be right there in the thick of it, 'cause I've had all of this fucked up US govt. I want