Secession means to secede, apart, or break away. In this case it would mean withdrawing from membership of a federation or body, especially a political state. There talking about when the Confederacy was formed.
"It was on November 6, 1860, not long after Abraham Lincolns inauguration, when Governor Madison Starke Perry called for Florida to prepare for a secession with other southern states in the organization of a confederacy."
On the 10th of January 1861 an ordinance of secession, which declared Florida to be a " sovereign and independent nation," was adopted by a state convention, and Florida became one of the Confederate States of America.
