I think your friend is mistaken. Lincoln did send a letter to the governor of South Carolina informing him that he was sending supplies by ship but he didn't specify a date.
My friend said that at this same time, Lincoln dispatched a letter to the commander of Fort Sumter informing him that he would soon be attacked by the Confederates, and that he was to take all steps to reduce loss of life, hold the Fort for one day, and then surrender it, which is exactly what happened.
On April 4th Lincoln sent a letter to Major Anderson telling him that the resupply effort was underway and that he hoped Anderson could hold out till the 11th or 12th. Lincoln also stated:
"It is not, however, the intention of the President to subject your command to any danger or hardship beyond what, in your judgment, would be usual in military life; and he has entire confidence that you will act as becomes a patriot and a soldier under all circumstances.
Whenever, if at all, in your judgment, to save yourself and command, a capitulation becomes a necessity, you are authorized to make it."
Lincoln at no time specified how long he wanted Anderson to hold out should an attack by the Confederates occur.
The Confederates did attack the Fort with cannon fire, yet no one was killed as a result of it. (Were they really aiming to kill anyone, or just making noise?)
Pictures taken of Sumter following the Confederate attack show quite a bit of damage. I have no doubt that the intent of the attack was to cause casualties, and it is only good fortune that nobody was killed during the bombardment.
You are correct, I didn't see that either, but of course I was relying on an anecdote told me by a friend who was outlining events in terms of Lincoln's cleverness at getting the Confederates to shoot first.
Pictures taken of Sumter following the Confederate attack show quite a bit of damage. I have no doubt that the intent of the attack was to cause casualties, and it is only good fortune that nobody was killed during the bombardment.
I doubt they would have bothered taking pictures of the parts of the fort that was undamaged. As to the gunners intentionally aiming to avoid killing anyone, that was just speculation on my part due to the circumstance that no one was actually killed during the shelling of the Fort. From what I've just read, it was something like 3,000 shells fired at Fort Sumter. At the link listed above, is letters from General Beauregard to Major Anderson informing him that he didn't really want to blow anyone to pieces.
Second letter from Beauregard to Anderson, April 11.
Major: In consequence of the verbal observation made by you to my aides, Messrs. Chesnut and Lee, in relation to the condition of your supplies, and that you would in a few days be starved out if our guns did not batter you to pieces, or words to that effect, and desiring no useless effusion of blood, I communicated both the verbal observations and your written answer to my communications to my Government.
I may be mistaken, but I don't think the Confederates really wanted to kill anybody.