Early June 1862, Maj. Gen. David Hunter transported Horatio G. Wright's and Isaac I. Stevens's Union divisions under immediate direction of Brig. Gen. Henry Benham to James Island where they entrenched at Grimball's Landing near the southern flank of the Confederate defenses.
The stage was set for the Battle of Secessionville. On the June 15th, Gen. Benham laid plans for the Union forces to make an early morning surprise attack on the Secessionville fort, a "reconnaissance in force" as he so called it. He would use approximately 3500 of his troops to make a frontal assault before daybreak, attacking to 2 structured waves. During that day and throughout the night Col. Lamar had his troops working on shoring up the fort's defenses. Lamar finally dismissed his men at 4:00 A.M. By this time the union forces comprising the 8th Michigan, the 7th Connecticut, 28th Massachusetts and 79th New York Highlanders were on the move, supposedly at the double-quick, advancing on the fort. However, advancing through the darkness, the troops had to negotiate through 2 hedge rows and open cotton fields now knee-deep in weeds. This resulted in breaking up the initial Union lines and slowing the advance. As the field narrowed approaching the fort, the left side of the Union front was pushed into the marsh and got bogged down in the mud. It also compressed the Union center, slowing the advance such that the second wave ran into the first complicating the advance even more.
