 Buckner, left alone in command, proposed a cease-fire to Grant while terms of surrender were negotiated.Grant's reply– that only "an unconditional and immediate surrender" could be accepted– made him a hero in Union eyes, and earned him the nickname "Unconditional Surrender" Grant.The collapse of Forts Henry and Donelson made Polk's position at Columbus untenable; the Confederates were forced to abandon "The Gibraltar of the West."