was returning with a great force from Pittsburg Landing.
Whatever it was, something had a very demoralizing effect upon the garrison, and the guns of the fort were no longer well aimed or rapidly fired.
On the night of June 4th, a great many explosions were heard in the fort, which indicated to the officers of the fleet that the enemy was preparing to evacuate.
The Flag-officer on receiving this intelligence, gave orders for the gun-boats to get under way at 4 o'clock on the morning of June 5th, and to move down the river in the following order: Benton, Mound City, Louisville, Carondelet. Cairo, and St. Louis.
(The Mound City had been fished up out of the river and repaired, but the Cincinnati was still at Cairo.)
Since the battle with the Confederate rams a new organization had been added to the Union fleet in the shape of a ram flotilla,commanded by a very gallant man, Col. Charles Ellet, of the U. S. Army.
These vessels were simply ordinary river steamers converted into ra