There is general agreement that Lincoln's actions on March 29, especially regarding Fort Sumter, constituted a decisive moment in his presidency. David M. Potter identifies March 29 as "the turning point of his policy" because the realization that General Scott's advice had been politically motivated caused Lincoln to order the Sumter expedition prepared. Richard N. Current also considers March 29 a "key" date. After the cabinet meeting on March 29, Current asserts, Lincoln "began to act as commander in chief." And Kenneth M. Stampp agrees that beginning with March 29, Lincoln "acted swiftly" on the Sumter matter and began taking decisive steps to fulfill the promise of his Inaugural Address.
But once again, it is more difficult to assess the motives and considerations behind Lincoln's decisions than to describe them. Was his order to prepare the Sumter expedition decisive? Was there no turning back? What would Lincoln do if word suddenly arrived that his earlier orders to reinforce Pickens had, in fact, been carried out? Would he still go ahead with the Sumter plan?
Lincoln himself later explained that the preparations he ordered on March 29 were not absolutely conclusive. In a message delivered to a special session of Congress on July 4, 1861, Lincoln stated that the Sumter expedition was "intended to be ultimately used or not, according to circumstances." He called the failure to reinforce Pickens "the strongest anticipated case for using" the Sumter expedition. Lincoln, therefore, implied that under certain circumstances, the expedition might be abandoned, such as news of the successful reinforcement of Fort Pickens.
Potter, following Lincoln's account, agrees that the President's orders of March 29 were not decisive. Always hoping for peace, and favoring the least provocative action that would still assure the principle of Union, Lincoln left the implementation of his orders contingent on future circumstances. Potter contends that "no irrevocable step" was taken by Lincoln until a week later, April 6, when he learned conclusively that Fort Pickens had never been reinforced. Only at this moment did Lincoln take "the decisive step" of ordering the relief expedition to sail for Sumter.
Both Current and Stampp, however, think that Lincoln's decision of March 29 was more conclusive. By that day, Lincoln's hopes for a peaceful resolution of the secession crisis were virtually nil. He fully appreciated the Confederacy's determination, and the likelihood the South would resist any kind of relief expedition. Nor would abandoning Sumter conciliate the Confederacy. Sumter's relief was never, therefore, tied to events at Fort Pickens. The same problem of authority would soon erupt at Pickens or some minor fort, or over the question of recognizing the Confederacy. Lincoln, therefore, approached Pickens and Sumter separately, though within the context of his general policy to maintain the Union and enforce the laws. As Stampp says, "all the evidence indicates that Lincoln had decided to supply Sumter as early as March 29," and there was every expectation that the plan would go ahead regardless of what happened at Pickens.
It seems likely that Lincoln's decision of March 29 to prepare the Sumter expedition was motivated by highly complicated considerations that blended aspects of these different points of view. By formally preparing a relief mission, Lincoln certainly signaled a greater commitment to holding Sumter than he had previously done. He was clearly rejecting the advice of those who would abandon the fort. At the same time, Lincoln probably recognized that "circumstances" might dictate the expedition's course. While he considered news of the failure to reinforce Pickens as "the strongest anticipated case for using" the Sumter expedition, it should be noted that the phrase "the strongest" does not mean "the only" case. Regardless of what transpired at Pickens, there might be reason to dispatch the expedition. Alternatively, a variety of considerations, other than news that Pickens had been reinforced, might cause this mission to be scrapped: a quick Confederate takeover of the fort; the sudden surrender by Major Anderson due to the accidental destruction of his food supply; undue delays in organizing the expedition; or, weather conditions that prevented its departure in sufficient time to save the garrison.
Finally, Lincoln may have wavered between different positions. At times, he may have been ready to suspend the operation should circumstances warrant. At other moments, he may have been fully convinced that it would be necessary to send it.
Bibliography: Potter, Lincoln and His Party, pp. xxvi, 361-63; Current, Lincoln and the First Shot, pp. 81, 193-96, 202-204; Stampp, And the War Came, pp. 278, 283-84; Lincoln, Works, eds. Nicolay and Hay, 6: 302; Nicolay and Hay, Lincoln, 3: 433-34.