Secretary of State William H. Seward eloquently argued for abandoning Sumter. Seward based his case on the impossibility of peacefully provisioning the fort. Since the attempt would involve military action, it would "probably initiate a civil war." While he would defend the Union by force if necessary, civil war was, next to disunion itself, a national calamity. The fundamental question for Seward, then, was how to restore the Union by a peaceful policy that would not provoke civil war.
Seward's solution was to allow the secession crisis to subside by avoiding new provocations. Southerners were fundamentally devoted to the Union, but this sentiment had temporarily been silenced by fears associated with Lincoln's election. Conciliatory policies, however, by denying to the disunionists new offenses, would permit loyal southerners to regain their governments and restore the Union. For evidence of the beneficial effects of conciliation, Seward pointed to the stalling of secessionist momentum after the initial surge.
Seward especially emphasized the good effect of conciliatory measures on the upper South, whose continued loyalty would help patriots in the deep South return to the Union. Time must be provided "for reason to resume its sway. Time will do this, if it be not hindered by new alarms and provocations."
As for Fort Sumter, Seward contended that even if held, it had no military value for the United States. It was only as a symbol, "a monument" of the government's "authority and sovereignty." He would continue to hold it as long as it could be done without involving problems greater than the advantages of continued possession. But, he warned, sending reinforcements or supplies would entail using military force, and would appear as though the government initiated conflict without adequate justification.
Seward stated that he would, in certain circumstances, advocate the use of force. But he "would not provoke war in any way now." And he would not initiate war "to regain a useless and unnecessary position on the soil of the seceding States," or one which could not be defended when in federal hands.
Bibliography: Lincoln, Works, eds. Nicolay and Hay, 6: 192-201.