LH this is a movie thread, but okay:

We've already gone around a coupla times on your unique definition of what constitutes war. It's not the one in the dictionary.

It ain't an invasion to move troops around in your own country. It's a rebellion when lawful troops of your country are fired upon by extra-legal forces, such as at Fort Sumter.

As for the riots in NYC, they were not just any riots, they were a well organized mini rebellion that took federal troops to put down over a period of days if not weeks. The organizers were no mere northerners, they were primarilly immigrants afraid for their jobs against the prospect of cheap black labor, according to historian David McCullough.

Your overall argument against 'Northern aggression' would do very well against the D-Day invasion as well.

As for slavery, I hope you agree with me that there is slavery going on right now. So who can tell?