How many states eventually ended up seceding from the Union?

• seven
  Only seven states -- South Carolina, Georgia, Florida, Mississippi, Alabama, Louisiana and Texas -- seceded at first. But after Lincoln's call for a militia to enforce federal authority, four border states -- Virginia, Arkansas, Tennessee and North Carolina -- seceded and joined the Confederacy.
• nine
  Only seven states -- South Carolina, Georgia, Florida, Mississippi, Alabama, Louisiana and Texas -- seceded at first. But after Lincoln's call for a militia to enforce federal authority, four border states -- Virginia, Arkansas, Tennessee and North Carolina -- seceded and joined the Confederacy.
• eleven
  Only seven states -- South Carolina, Georgia, Florida, Mississippi, Alabama, Louisiana and Texas -- seceded at first. But after Lincoln's call for a militia to enforce federal authority, four border states -- Virginia, Arkansas, Tennessee and North Carolina -- seceded and joined the Confederacy.