It wasn't US property once secession took place. If you think that the South were agressors, than why were Peace Commissioners from the Confederate Government trying to persuade the Feds to handover the fort from Dec 1860 until April 1861? If they wanted to go to war, they could have reduced it immediately. All the South wanted was to be "left alone", and Abe Lincoln wasn't about to do that. He took a course guaranteed to provoke conflict.
If you think that the South were agressors, than why were Peace Commissioners from the Confederate Government trying to persuade the Feds to handover the fort from Dec 1860 until April 1861?
The so-called 'Peace Commissioners' were not authorized by the confederate congress until February 1861. And their purpose was to obtain recognition of confederate sovereignty from the Lincoln Administration and only then negotiate on issues such as who owned what. Unless Lincoln was willing to surrender to southern demands then there was nothing to negoitate. The southern delegation was not willing to discuss an end to the rebellion. So the south chose aggression in the form of bombarding Sumter.
He took a course guaranteed to provoke conflict.
The south could have avoided conflict by waiting Lincoln out. Instead, after a half-hearted attempt at negotiation, they chose war. And suffered the consequences.