Did the Confederate States legally secede from the Union?

The states decided that since they had freely joined the union, they would freely leave the union. There was  no law saying they could never leave.

 https://www.northjersey.com/story/opinion/readers/...

uh - you know there was a war about this, right?

The Constitution doesn't mention secession nor provide any mechanism for it.  Some people thought that was implied (if you view the Constitution as a limiting document--that is, anything not explicitly prohibited is allowed--then you could say the right of secession is implicit), others saw it more like a 'roach motel' paradigm (you can check in but you can never check out).

Of course, if you want to be a stickler for the law, it was probably illegal (and treasonous) for the US to secede from England!

There was no legal method of seceding from the Union.   So it basically came down to different viewpoints,   and  pistols at dawn, so to speak.........

and the South fired first,   Firing on Fort Sumter,  which was an official "attack" on the United States of America. 

Make no mistake....it was flat out TREASON. 

Every last OFFICER of the Confederacy , swore an OATH to the Uphold the Constitution....when they were officers of the UNITED STATES MILITARY. 

By joining and supporting the Confederacy......it was an act of TREASON 

It was an armed INSURRECTION,  against the GOVT of the UNITED STATES. 

they were NOT  patriots, or freedom fighters, or whatever else they wished to call themselves......

they were TRAITORS, who sought to destroy the UNION and current form of Govt. 

And they may have fired first,  but we fired LAST......and they LOST. 

Every last one of them,  should have been HUNG for HIGH TREASON. 

But at the time........after 4 years of bloody war...... the country needed to HEAL,  and the decision was made, to not press charges,  on the clearly defeated enemies. 

There was no Constitutional procedure for secession. Like Hillary's email, no legal punishment was provided.

No. Which was a big sticking point with Lincoln.

No, they didn't. They left by force, which is what caused the war. 

The confederate states lost because the conservatives are weak. 

The Constitution has no provision for secession.  There is no legal way to secede.  In addition, the Confederate military leaders swore a life-long oath of loyalty to the US Constitution.  Then they violated that oath, and attacked the nation governed by and sworn to uphold that Constitution.  Said actions meet the Constitutional definition of 'Treason.'

They did, indeed.  And they went to war to try to enforce it.  They lost.  Badly.