It's recorded in a number of sources, as Randall and Eisenschiml document.
Randall was fair and balanced toward the Confederacy. He even acknowledged that the Confederacy was moving toward emancipation in early 1865 and that this indicated the Confederacy may well have ended slavery even if it had survived the war.
The Radical Republicans were starting to suspect that Lincoln planned on allowing the Confederacy to continue by default, by not taking any action against it. The Radicals even voiced this suspicion on the Senate floor.
Jefferson Davis threw a monkey wrench into Lincoln's plan by foolishly cutting off the food supply to the Fort Sumter garrison. He then wrecked Lincoln's plan by firing on Fort Sumter, even though he had been assured that the federal naval convoy would only offload food as long as they were not fired upon. We know that Gideon Welles, the Secretary of the Navy, specified this in the operations order for the convoy: they were not to fire unless fired upon and were not to offload any weapons or ammo unless fired upon.
I swear, if Jefferson Davis wasn't on the Radicals' payroll, he should have been. The attack on Fort Sumter was a dream come true for the Radicals.
You say, because you believe Randall and Eisenschiml, that Lincoln was prepared to evacuate Fort Sumter in exchange for reinforcing Pickens. That is just a bold face lie. Lincoln never entertained the idea of evacuating Sumter or Pickens.
In Lincoln's first inaugural address: "The power confided to me will be used
to hold, occupy, and possess the property and places belonging to the government and to collect the duties and imposts: but beyond what may be necessary for these objects, there will be no invasion." (The Annals Of America, Vol. 9, Encyclopaedia Britannica, Inc., 2003, p. 252)
Lincoln made it clear that he would never let the Forts go. And even before the inauguration Lincoln, when he was President in waiting, he wrote to Frank Blair: "On the forts, Lincoln was no less clear, '
If the forts shall be given up before the inaugeration, he wrote to Frank Blair, an elder statesmen who had once been a part of Andrew Jackson's kitchen cabinet, the
General must retake them afterwards'. He asked Washburne to assure Scott '
to be as well prepared as he can to either hold, or retake, the forts, as the case may require, at, and after the inaugeration'." (Days Of Defiance, Maury Klein, Alfred A. Knopf Inc., 1997, p. 137)
And, well on their way to the firing on Sumter, March 27, 1861, William Russel, famous reporter for the London Times, had opportunity to speak to Seward. "Russel asked about the rumors in the New York papers that Fort Sumter would be evacuated. '
That is a plain lie', Seward retorted. 'No such orders have been given. We will give up nothing we have--abandon nothing that has been entrusted to us'. If people would only read these statements by the light of the President's inaugural, they would not be deceived." (Klein, p. 350)
The problem was, Seward and Lincoln had been deceiving the Southern Commissioners that Sumter would be evacuated. Which is why there were rumors. But Lincoln never had any intent to let the forts go.
Why didn't Lincoln just send the message to Gov. Pickens and Anderson, that Anderson would evacuate the Fort? That's all he needed to do. He didn't even mention any evacuation.
Food would be supplied by the South for the soldiers at Sumter once they evacuated.
No need for any Navy force to be there at all. No need for any reinforcements.
And why was Lincoln sending a force to Fort Pickens to reinforce it, at the same time he was sending a force to Sumter? If, as you say, he was interested in any exchange of Pickens for Sumter?
And Jeff Davis did exactly what he should have. He waited patiently until the deception of Lincoln was fully exposed concerning Sumter. And with the Naval force on it's way to reinforce, gave Beauregard the authority to fire.
Quantrill