[DiogenesLamp]

And yet you do while ignoring all the evidence that had the South allowed Fort Sumter to be resupplied then reinforcements would not have been landed.

One more day and Anderson would have left. Why would they want to throw that away? Gone would be the Federal threat to their trade, all they needed was one more day.

And then the warships showed up, confirming their worst fears that Lincoln had no intention of giving the fort up peaceably, despite Seward's assurances to them.

Lie to them, mislead them, then send troops and gunboats with orders to attack them?

[BroJoeK]

DiogenesLamp: "And then the warships showed up, confirming their worst fears that Lincoln had no intention of giving the fort up peaceably, despite Seward's assurances to them."

But Lincoln did intend to give up Fort Sumter peacefully, in exchange for a promise by Virginia not to secede.
A fort for a state, thought Lincoln, would be a good bargain.

Lincoln did not wish to give up Fort Sumter for free.