Unless you think I'm the author of the history website from which I posted a link to, I'm not the one who "is rewriting anything."
#122 | POSTED BY KANREI
1) I would not confuse you for the author of a history website.
2) The website "from which you posted a link to" says nothing at all about the North not knowing they were resupplying Sumter. I surmise that you are conflating Major Anderson's move to Sumter from Moultrie with Lincoln's resupply expedition.
3) You are attempting to re-write the rules of good and decent grammar, by which a writer should use just one preposition per verb. That one preposition should not come at the end of the phrase.
Here's what I read about Sumter at the link you provided:
On April 10, 1861, knowing that resupplies were on their way from the North to the federal garrison at Fort Sumter in the harbor of Charleston, South Carolina, provisional Confederate forces in Charleston demanded the fort's surrender. The fort's commander, Major Robert Anderson, refused.