11.
Eleven
Texas was the seventh state to secede.
The Confederate States Of America was formed by eleven states that seceded from the United States.
There were 11 states that seceded to form the Confederate States of America :AlabamaArkansasFloridaGeorgiaLouisianaMississippiNorth CarolinaSouth CarolinaTennesseeTexasVirginia(see related question)
The Southern states seceded from December of 1860 to April of 1861.
The upper southern states seceded when Lincoln was elected president of the United States.
No states seceded from the Civil War. Seven states had seceded from the USA by the time of Fort Sumter, and four more seceded as a result of it. Later one new state, West Virginia, seceded from Virginia.
None of the Border States seceded even though they were slave states.
The Confederate States of America was formed in February 1861 by seven states which had seceded from the Union.
None of them did. There is a link below to a question about states that seceded in the 19th century.
Eleven slave states seceded. This included Texas, Louisiana,, Mississippi, Alabama, Arkansas, Georgia, Florida, North Carolina, South Carolina, and Virginia. Virginia seceded, then West Virginia seceded from Virginia and rejoined the Union.
James Buchanan was president when seven Souther states seceded. Four more seceded after Abraham Lincoln took office.