Did You Know That The Confederacy Was An Independent Country?

I was taught in public school that the South didn't really leave the Union, and that the North was trying to free the slaves. But as I got older and did my own research I found out that the States had a right to succession and the Civil War wasn't really fought over slavery. Basically, the North didn't want to loose the South because it was such a huge revenue for the North because of Tariffs, so once they left the Union, Lincoln attacked a sovereign country. Also, Lincoln thought of Blacks as less than human, a little fact that is left out of most textbooks. The South wanted freedom from a tyrannical government. Did anyone else realize this? My thoughts about Lincoln have gone way down in the last year or so.