Zero percent. There won't be a civil war in the US. To have a civil war you first need to have MEN.
There are significant differences between the standing men your country had back then in the 19th century and the males that it has right now:
Firstly, back then, 90% or more of men were self employed. Working for someone else, unless you were a young man, was often seen as a humiliating position. Now, most American (and Western) males are corporate wageslaves closely monitored by the HR Gestapo. Just one little politically disagreeable remark in your social media can get you fired. Do you really expect modern males to take up arms and organize in factions?
Secondly, debt. Not only are most modern males wageslaves, they're generally very VERY indebted. Being out of a job for these people would mean not to be able to meet mortgage payments for the house, the car, etc. The banks have most of the population grabbed by the balls. Even if you're not in debt being a political miscreant can bar you from access to credit and thus from ever owning a home, getting a car or getting emergency loans to get out of a rut, which could lead you to becoming homeless.
Thirdly, the males are extremely emasculated and controlled by the women. Married males do not call the shots in their households. The institution of marriage has been meticulously legally re-engineered to ensure the wives keep their husbands in check. When you marry a woman, you are marrying a government's prison guard that will take your stuff and make you a slave (alimony, etc) if you misbehave. Think of middle aged men; boomers, gen x's, etc... Do you think the wife is going to allow hubby to take up on arms, organize a local militia with the other local men to defend themselves collectively? And forget the younger guys, they're being brainwashed to be afraid or outright hate firearms.
So... what CAN you expect? There won't be a civil war, because the men are chained, but there WILL be lots of political unrest.
