What were some reasons for southern states to secede from the Union?

Answer 1

Slavery was the main issue- they wanted to keep slaves and the Southern way of life. It became obvious that the United States might

eventually outlaw slavery by a Constitutional amendment. They also hated the tariffs which had been established to protect Northern industries.
The Southern States in the United States believed they had good reasons for seceding from the Union. They were convinced that slavery would fail to be extended into the new American Territories and that there would be attempts to abolish slavery. Southern leaders predicted that their slave States would become outnumbered in the US Congress, and anti slavery movements in the North would ultimately damage their economy and way of life. They felt even worse when the Republican, Abraham Lincoln was elected US President. Although Lincoln assured the South that he had no intentions of, or even had the power to damage slavery, his party, the Republicans, were an anti slavery party.

Tariffs imposed by the Federal government was also an economic problem for the South.