In february 1861, the seceding states declared themselves to be an independent
country known as
the southern united states.
the confederate states of america.
o the southern states of america.
the democratic states of america.

The Confederate states of America

Explanation:

on February 1861 the seven (7) southern states of Mississippi, Florida, Alabama, Georgia, south Carolina, Texas, Louisiana, seceded from the United states of America to form their own independent republic which they will call the Confederate states of America.

this secession was caused mostly because the Northern states did not support slavery due to the state rights , just like the south and the south decided to secede to form their own republic and this eventually gave birth to the civil war.