What are the reasons why the south succeeded from the union?

The south did not succeed from the union. It SECEDED from the union. Spelling counts, unless you are illiterate.

He spelt it right you dumb f*@k. Don't correct peopples spelling if you cant spell yourself. Wow, you have to be the biggest jacka$$ in the world.

Actually Secession is spelt...well...secession.

But anyway, they seceded from the union for many reasons.

Note there was a lot of tension between the North and the South.

Alan~Farmer's book "THE AMERICAN CIVIL WAR: CAUSES, COURSE AND CONSEQUENCES, 1803-77 fourth edition" is a really good and helpful book, trust me.