Lincoln ordered the Powhattan to Sumter, not Pickens.
First of all it was spelled Powhatan. Second of all, Lincoln did sign orders that ended up sending the Powhatan to Fort Pickens. When Navy Secretary Welles discovered that the ship wasn't going to Fort Sumter as he thought, he went to see Lincoln. From "Days of Defiance" by Maury Klein:
Welles marched to the White House, where he found Lincoln alone at a table. The president looked up from his writing, saw the dark cloud on Welles's heavily beared face, and sighed, "What have I done wrong?" Welles showed him the papers [signed by Lincoln] and pressed for an explanation.
Lincoln had signed orders without reading them. From "Days of Defiance" again: "Lincoln looked mystified and took the whole blame for the mixup on himself." Even after this, Lincoln still kept the Pickens mission secret from Welles. The Pickens mission had been planned without Welles knowledge even though it involved Navy ships and officers.
Lincoln then gave orders to Seward to return the Powhatan to Captain Mercer (i.e., to the Sumter expedition). Seward sent an order to do just that. Seward signed the instruction, "Seward," and did not say this latest instruction was at the order of Lincoln. By the time the order reached the Powhatan, it had already sailed on its Lincoln-authorized mission to Fort Pickens. The note from Seward was carried on a fast ship that managed to catch the Powhatan, but Porter, the man in charge of the Powhatan, ignored it saying that he had received his orders directly from the president, who had not rescinded them. He proceeded to Fort Pickens where he tried to enter Pensacola Harbor flying English colors, a false flag act. In July, Lincoln stonewalled Congress about his orders that violated the armistice/truce at Fort Pickens. No copy of the secret orders survived.
Hell of a way to run the government.
Sure, Lincoln was brand new at the job, but he did order the USS Powhatan returned to the Fort Sumter mission.
The important point here remains that Confederates (and you?) apparently see this as adequate excuse to start Civil War.
I'm saying that's because some excuse was all they really wanted.