Emilio, Luis F., History of the Fifty-Fourth Regiment of Massachusetts Volunteer Infantry , 1863-1865

[121] the land batteries, ‘Ironsides,’ and two monitors opened a terrific bombardment on Wagner which lasted forty-two hours. Under its protection our sap progressed in safety. Wagner dared not show a man, while the approaches were so close that the more distant batteries of the enemy feared to injure their own men. Our working parties moved about freely. Captain Walker ran some one hundred and fifty yards of sap; and by noon the flag, planted at the head of the trench to apprise the naval vessels of our position, was within one hundred yards of the fort. The Fifty-fourth detail at work there on this day had Corp. Aaron Spencer of Company A mortally wounded by one of our own shells, and Private Chas. Van Allen of the same company killed. Gregg's capture was again attempted that night by Major Sanford's command. When the boats approached near, some musket-shots were exchanged; and as the defenders were alert, we again retired with slight loss.

Daylight dawned upon the last day of Wagner's memorable siege on September 6. The work was swept by our searching fire from land and water, before which its traverses were hurled down in avalanches covering the entrances to magazines and bombproofs. Gregg was also heavily bombarded. As on the previous day our sappers worked rapidly and exposed themselves with impunity. The greatest danger was from our own shells, by which one man was wounded. Lieutenant McGuire, U. S. A., was in charge a part of the day. He caused the trenches to be prepared for holding a large number of troops, with means for easy egress to the front. Late that evening General Gillmore issued orders for an assault at nine o'clock the next morning, the hour of low tide, by three storming columns under General