On board the U.S.S. Santiago de Cuba during the assault by the fleet on Fort Fisher, 15 January 1865. When the landing party to which he was attached charged on the fort with a cheer, and with determination to plant their colors on the ramparts, Williams remained steadfast when they reached the foot of the fort and more than two-thirds of the marines and sailors fell back in panic. Taking cover when the enemy concentrated his fire on the remainder of the group, he alone remained with his executive officer, subsequently withdrawing from the field after dark.