Short answers, pulled from the story.
Colonel William Moultrie commanded a garrison of 413 men from the 2nd South Carolina Regiment alongside 22 artillerymen from the 4th Regiment. Captain De Brahm supervised the unfinished southern tip while northern walls stood only partially constructed.
A fleet of nine British warships approached Sullivan's Island under Admiral Sir Peter Parker on the 28th of June 1776. The wooden structure absorbed heavy bombardment rather than shattering like traditional masonry would have done.
Osceola died of malaria in January 1838 and was buried near the front gate of the fort where soldiers maintained a grave thereafter. The United States Army detained Native American individuals at this location for fifty years before Osceola died of malaria in January 1838.
General Sherman marched through South Carolina in early 1865 forcing Confederate soldiers to abandon the ruins of Fort Moultrie. They evacuated the city of Charleston shortly after leaving behind only scattered remnants of their former stronghold.
On the 15th of August 1947 the Army lowered Fort Moultrie's flag ending one hundred seventy-one years of continuous service. Changes in military technology including submarines and nuclear weapons made traditional seacoast defense strategies unviable moving forward.