The Accidental Armor

The most important material decision in the Battle of Fort Sullivan was made for practical reasons, not strategic ones. Palmetto logs were what was available on the South Carolina coast in large quantities. They were not chosen because anyone knew they would absorb cannon fire. They were chosen because they were there.

The property that made palmetto logs effective under bombardment is the same property that makes palmetto wood difficult to use in ordinary construction: the fibers run in all directions rather than along a grain, which means the wood doesn't split cleanly, doesn't take nails easily, and doesn't behave predictably when cut. In a carpenter's hands, palmetto is a frustrating material. In the path of a British cannonball, that same randomness of fiber becomes protective. The ball buries itself rather than creating the lethal wooden shrapnel that a pine or oak wall would produce.

General Charles Lee thought the fort was indefensible. His reasoning was correct for a conventional fort: an unfinished earthwork on a sand island, with the south wall incomplete, facing nine warships. His reasoning did not account for the specific material properties of what the wall was made of.

When I stand at Fort Moultrie today and look at the harbor, I think about the contingency of the whole thing. Different wood, different outcome. Parker's fleet might have suppressed the fort's fire by mid-afternoon. Clinton's troops might have found a way across the channel. The southern campaign might have started four years earlier, with a British garrison in Charleston from 1776 rather than 1780.

Or not. History doesn't reveal its alternatives. But the palmetto tree on the South Carolina flag is a reminder that what looks like strategy is sometimes just the properties of local timber.