On April 10th, 1862 Captain union general Gilmore demanded siege operations against Fort Pulaski. Captain Gilmore, a staunch advocate of the new naval rifled guns, became the first officer to use guns to knock out the enemy stone fortification effectively. There were over 5,000 artillery shells which fell on Pulaski from a range of 1,700 yards during the short siege. It resulted in the fort's surrender after its walls were breached.