Grant correctly concluded that for the Confederates to hit so hard on the right, they must have weakened their line somewhere else.  Seizing the initiative, he told General Smith to "take Fort Donelson."  Smith had his troops uncap their guns (so the men would not be tempted to fire, risking greater casualties) and fix bayonets.  With the Second Iowa Infantry spearheading the attack, Smith led the assault against the Confederate lines on this ridge.  Smith's division routed the 30th Tennessee Infantry and captured and held the earthworks, thus controlling this position on the night of the 15th.  Before the attack could be renewed the next morning, Grant and Buckner were already discussing terms for surrender.