There are three stages, or levels of action, to becoming independent.
1 Declaration of independence
2 Implementation of independence
3 Maintenance of independence
As discussed earlier, it is the State of New Hampshire that is separating. Has any state, ever, separated from the United States?
The first instance that might be considered separation is that of the potential for some states to separate from the other states of the United States has already been mentioned.
U.S. constitution, Article VII
“The Ratification of the Conventions of nine States, shall
be sufficient for the Establishment of this Constitution
between the States so ratifying the Same.”
What would have happened if the first nine states to ratify the constitution, thus establishing the constitution, were the only ones to ratify the constitution? How would those nine states view the remaining four states? Would those states have succeeded in seceding from the United States, as defined in the Articles of Confederation?
The concept of secession was actually debated over and over prior to the civil war:
“Unlike the Articles, the new Constitution also did not forbid
secession by any state. In fact, it was rather silent on the
subject of secession. But, is its silence evidence in support
of secession? It does not necessarily prove that secession
was possible except for the fact we know from history that
secession was a very real possibility way before the Civil War.”
The next instance occurred with the Civil War.
James Buchanan was president of the United States in 1860, the year Abraham Lincoln was elected president. Interestingly, it appears that the southern states wished to leave peacefully, similar to the current secession movement in New Hampshire.
Some of the southern states vowed to secede if Lincoln was elected to the presidency. Lincoln was elected on November 6th, 1860.
The South Carolina Ordinance of Secession was adopted on December 20, 1860.
http://www.civilwarcauses.org/ordnces.htm#South%20Carolina
The Mississippi ordinance of secession was declared on January 9, 1861.
http://www.civilwarcauses.org/ordnces.htm#Mississippi
The Florida Ordinance of Secession was passed January 10, 1861.
http://www.civilwarcauses.org/ordnces.htm#Florida
The Alabama Ordinance of Secession was accepted on January 11, 1861.
http://www.civilwarcauses.org/ordnces.htm#Alabama
Georgia’s Ordinance of Secession was passed January 19, 1861.
http://www.civilwarcauses.org/ordnces.htm#Georgia
Louisiana’s Ordinance of Secession was adopted on January 26, 1861.
http://www.civilwarcauses.org/ordnces.htm#Louisiana
The Texas Ordinance of Secession was adopted on February 1, 1861.
http://www.civilwarcauses.org/ordnces.htm#Louisiana
James Buchanan was president until March 4, 1861. Lincoln was inaugurated on that date. The United States did not go to war over these secession ordinances.
Originally, South Carolina had owned Fort Sumter, but it, along with other forts, were ceded to the United States in 1805. Thus, in 1861, Fort Sumter was a United States property.
On April 12, 1861, Lincoln attempted to re-supply Fort Sumter. A battle ensued, kicking off the Civil War.
The Virginia Ordinance of Secession was adopted on April 17, 1861, and ratified (by the people ?) on May 23, 1861.
http://www.civilwarcauses.org/ordnces.htm#Virginia
The Arkansas Ordinance of Secession was adopted and passed on May 6, 1861.
http://www.civilwarcauses.org/ordnces.htm#Arkansas
The North Carolina Ordinance of Secession was adopted on May 20, 1861.
http://www.civilwarcauses.org/ordnces.htm#North%20Carolina
The Tennessee Ordinance of Secession was sent to referendum on May 6, 1861 and approved by the voters on June 8, 1861.
http://www.civilwarcauses.org/ordnces.htm#Tennessee
The Missouri Ordinance of Secession was approved October 31, 1861.
http://www.civilwarcauses.org/ordnces.htm#Missouri
The Kentucky Ordinance of Secession was adopted November 20, 1861.
http://www.civilwarcauses.org/ordnces.htm#Kentucky
Seven states had already seceded by the time the Civil War commenced at Fort Sumter. More than three months had elapsed between the first secession and the first battle of the Civil War.
I have not been able to find any record of any legal action taken to address the secessions, and if anyone has any info, it would be greatly appreciated.