The crescent moon on the flag of South Carolina were added as a tribute to the decorative crescent that was on the South Carolina military uniforms during the Revolutionary War; the palmetto tree was added during the Civil War as the South Carolina state tree. The flag was updated and revised several times before it achieved the design seen on the current flag.
Colonel William Moultrie designed the crescent flag on blue because it was the same color as the soldier’s uniforms during the Revolutionary War in 1775. About 100 years later when South Carolina seceded from the union, the people of the state wanted a new flag to commemorate their new status. They chose to start with the old flag but added a palmetto tree in the center since this is the state tree of South Carolina. The reason why the palmetto tree is the state tree is not known for certain, but the rumor is that it goes back to Colonel Moultrie and his defense of Sullivan’s Island against the British in 1776. The British fired cannons at the fort there, but the cannonballs could not destroy the fort because it was made of palmetto trees. The cannonballs would just sink right into the soft logs instead of breaking them. South Carolina chose to keep the flag from the Civil War, and it’s the one they use today.