I’ve seen this formal declaration of war by the CSA mentioned several times.
Do you have a link to it?
Even though I mention it frequently, still virtually nobody has heard of it, or understands its significance.
Now I wish I could remember where I first saw the Confederacy's declaration of war, or the link to it, but I'm certain we've had many discussions of it, going back some years.
The neo-Confederate response is along the lines of, "oh, that wasn't really a declaration of war, just like Fort Sumter and the others weren't really acts of war..."
Here is my link to the Confederacy's Declaration of War on the United States.