Rives Advice
The delegates reasoned that the abandonment of these forts would remove a source of friction that could erupt into civil war. By avoiding war, the administration would encourage unionists throughout the South and prevent the eight slaveholding states still in the Union from leaving to defend their slaveholding brethren. Abandoning the forts would also provide time to find a way to return the secessionist deep South to the fold, whereas war would permanently sever the Union.
Bibliography: Current, Lincoln and the First Shot, pp. 34-35; Potter, Lincoln and His Party, pp. 353-58.