I agree with Greg Taylor, Lincoln's handling of the Ft. Sumter crisis, because he, had to taek it on-the-fly. He was inaugurated and literally a few hrs later he had a full blown war crisis on his hands. He had to act decisively, yet deliberately, at the same time. With few guidelines in his experience of the gov't itself with which he might refer.
P.S. Abnother turning point of his administration was Lincoln's quickly establishing his authority and leadership over his (Potentially devisive) Cabinent of strong men in their own right, some of whom believed they should have been President rather than Lincoln and all of whom, had little confidence in his ability to lead the country in the devloping crisis. .