Gideon Welles, Navy secretary, expressed "doubts of the wisdom" of a relief expedition. Welles argued that military experts questioned the wisdom of the enterprise, and even if successful, it would lead to a battle for which the government would be considered the aggressor. Public opinion was under the impression that Sumter was to be evacuated, and would understand the conditions that necessitated its abandonment.
In sum, Welles was "not prepared to advise a course that would provoke hostilities." The attempt to provision Sumter would not gain the government any advantage, while "a failure would be attended with untold disaster."
Bibliography: Lincoln, Works, eds. Nicolay and Hay, 6: 208-10.