I disagree. The Confederacy and SC made several attempts to end the matter peacefully. Meet with them. Conduct negotiations. At least make some attempt at a peaceful settlement. Let tempers calm. Maybe Lincoln could have convinced them to rejoin the union.
South Carolina, Mississippi, Florida, Alabama, Georgia, Louisiana and Texas all seceded before the special session of Congress began 4 Mar 1861. When that session ended, the seceded states were still seceded. No invasion, no declaration of war. Lincoln waited until Congress was out of the way and then attacked.
That is absolutely ridiculous. After getting Lincoln to agree that they were, in fact, independent you expect the rebels to agree to reunification? Why would they do that? They launched their rebellion because they saw Lincoln as a threat to slavery. Lincoln wasn't going away. Slavery wasn't going to become any less important in the weeks or months to come. But you believe that there was a chance that the confederate congress would change their mind, the Davis regime would fold it's tent, and everyone would reunite under Lincoln's leadership. All while holding hands and singing 'Kumbaya' no doubt.
No discussions with the so-called peace commissioners was possible because nothing was open for discussion until recognition was bestowed. Peaceful settlement was possible only if everything was open for discussion and that was not the case. Davis didn't want it that way.