[PeaRidge]

You said: “...the Confederacy...formally declared war on the United States, on May 6, 1861.

That is wrong. A formal declaration of war on the Union was never passed by the Confederate Congress.

[BroJoeK]

Pea Ridge: "You said: '...the Confederacy...formally declared war on the United States, on May 6, 1861'. "

Pea Ridge: "That is wrong. A formal declaration of war on the Union was never passed by the Confederate Congress."

It's odd you say that, since the link to the Confederacy's declaration has been posted here many times.

Confederacy's Declaration of War on the United States, May 6, 1861.

Of course, the Union never formally declared war on the Confederacy, because they treated it as a rebellion, which never gets a formal declaration of war.
However, Congress did approve all of President Lincoln's actions in that regard.