 The 3rd Missouri Infantry Regiment defended the rifle pits between the two forts and the 6th Missouri Infantry Regiment manned a second line of rifle pits.The 1st Confederate Battalion held Winkler's Bluff, and the 1st Missouri Cavalry Regiment, the 3rd Missouri Light Battery, and a unit of sharpshooters from Arkansas were positioned four miles up the Big Black River.On April 16 and 22, eight Union Navy gunboats and nine transports went past the fortifications at Vicksburg and Grand Gulf; two of the transports were destroyed.