Regiment and 16th Mississippi Infantry Regiment under Lieutenant Colonel James H. Duncan of the 19th Mississippi Infantry Regiment along with artillerymen and a few troops from Lane's brigade, for a total of about 350 men, held Fort Gregg. Nathaniel Harris personally commanded the 19th Mississippi Infantry Regiment and the 48th Mississippi Infantry Regiment and a few artillerymen, totaling about 200 men, in Fort Whitworth. There were two three-inch rifled guns in Fort Gregg. Brigadier General Reuben Lindsay Walker, artillery chief of the Third Corps, removed the four rifled guns from Fort Whitworth before the Union attack because he was convinced that they would be captured by the attackers if he did not. The defenders of the forts collected and loaded extra rifles and positioned extra ammunition along the walls in preparation for the attack. Led by the brigade of Colonel (Brevet Brigadier General) Thomas O. Osborn and two regiments of the brigade of Colonel George B. Dandy of Brigadier General Robert S. Foster's division, the Union force formed on a low ridge south of the fort as soon as they arrived and then promptly proceeded with the assault. Colonel Harrison S. Fairchild's brigade formed as a reserve behind Osborn and Dandy's brigades. Gibbon's artillery, the Third Vermont Battery of Captain Romeo H. Start and a section of the First New York Independent Battery under Lieutenant William Sears, who were borrowed from Fort Fisher by Lieutenant Colonel Peter S. Michie because the XXIV Corps artillery had not come up yet from Hatcher's Run, silenced Fort Gregg's guns. A ditch partially filled with water surrounded Fort Gregg. After crossing a field of deadly fire to reach the fort, many of the attackers ran into the ditch only to be mired in water and mud. Wounded men risked drowning unless helped out of the water. Soldiers of the 67th Ohio Infantry Regiment reached the ditch first but could not work their way around to the rear entrance due to the water in the ditch. The 62nd Ohio Infantry Regiment lost many men in their advance and struggled to gain footholds in the muddy ditch to climb the parapet. Colonel Dandy's brother, Major James H. Dandy, commanding the 100th New York Infantry Regiment, was killed trying to reach the rear of the fort. Corporal and Color-Bearer John Kane of the 100th New York Infantry was awarded the Medal of Honor for his gallantry in