Fort Pulaski National Monument in Savannah, Georgia, celebrates its 84th birthday today, October 15. Brick masonry harbor forts like Fort Pulaski were thought to be impregnable until an astonishing thing happened in April 1862. After April 11, 1862, it would never again make sense to build a harbor fort of brick masonry.

A young Polish nobleman by the name of Casimir Pulaski fought for the American cause in the Revolutionary War. Pulaski, dubbed the “Father of American Cavalry,” died on October 11, 1779, two days after being wounded during the Battle of Savannah. Three decades later when the Federal government finally got around to building a fort to guard Savannah harbor, naming it for Pulaski seemed the right and proper thing to do. (It’s a good thing they decided not to use his full name, which was Kazimierz Michał Wacław Wiktor Pułaski herbu Ślepowron.)

If you find yourself in Savannah (lucky you), try to find a few hours to visit Fort Pulaski National Monument and see for yourself the imposing structure named in honor of that long-dead Polish nobleman. You’ll see a remarkable fort that is remarkably well preserved. You’ll see a fort that tells an important story too, for it was on the receiving end of what proved to be one of the most influential artillery bombardments in the history of warfare. Seldom has any historical era been ended so abruptly, so decisively, so utterly without question.

To appreciate what happened here you need to know something about the basics of harbor fort construction and mid-19th century naval weapons. As logic might suggest, you built the former in consideration of the latter’s capabilities.

Fort Pulaski was built during 1829-1847 to guard Savannah’s harbor against enemy warships. To describe the fort efficiently you would say that it was a state-of-the-art structure with 8-foot thick brick masonry walls and a moat seven feet deep and 48 feet wide (thus to discourage land-based attacks). The fort could be constructed of brick masonry because the smoothbore naval cannons of the time were woefully inaccurate and could not concentrate their fire on any particular part of a coastal fortification unless the warships drew perilously close to the fort and became big, fat targets for the fort’s own guns. Multiple-tiered forts like Fort Pulaski sported so many heavy-caliber guns that any attacking naval force, especially one maneuvering in a confined space like that before the fort, was almost certain to take an appalling beating.

If you take a closer look at Fort Pulaski’s construction, you’ll realize that it’s actually quite ingenious. Some 25 million bricks were needed to construct the fort, and it had to be built on the soggy soil of Cockspur Island. So the engineers designed a bottom for portions of the fort, allowing them to float in the marsh in barge-like fashion by displacing a mass of soggy soil and water equal to their own weight. Imagine that.

When the Civil War broke out in the spring of 1861, Savannah’s citizenry rested easy in the belief that Fort Pulaski was impregnable. Not so. A bombardment only a year later forced the surrender of the fort.

Two things happened that the fort’s designers did not anticipate. First, advances in weaponry produced big rifled cannons that were amazingly accurate. By early 1862 the Union already had Parrott and James Rifled cannons that could fire heavy projectiles a distance of up to four or five miles and repeatedly hit a target the size of a house. Aimed at, say, the front wall (scarp) of a brick masonry fort, cannons like that could pound it to rubble fairly quickly.

Another surprise was the positioning of Union artillery batteries on Tybee Island within range of the fort. No warships had to be risked in close quarter battle. Instead, beginning in February, Union engineers began moving 36 heavy guns, including rifled cannons, to firing positions ranging from 1,600 yards to around two miles from the fort. The range of the fort’s smoothbore cannons was only about half a mile.

On April 10, 1862, the Union artillery opened fire on the essentially helpless Fort Pulaski. Thirty hours later, on April 11, the big rifled cannons had breached the fort’s southeast scarp and Union troops were being readied to assault the fort. It was clear to the fort's defenders that the fort’s magazine, which contained 40,000 pounds of gunpowder, could be struck by one of the big projectiles passing through the fort. If the powder magazine were to blow up, the fort’s doom would be sealed and a goodly number of the garrison would be singing with the angels. The Confederate commander, Colonel Charles H. Olmstead, wisely surrendered the fort.

It had been a very one-sided fight. Confederate dead and wounded accounted for 364 of the battle’s 365 casualties.

The fort was repaired in less than two months and remained in Union hands for the rest of the war, thus preventing Confederate use of the port of Savannah. The fort’s garrison was resupplied courtesy of the Union navy, which controlled the sea approaches to the harbor. Fort Pulaski’s relative isolation was finally ended in December 1864 when Sherman’s March to the Sea campaign ended with the capture of Savannah.

Fort Pulaski’s defeat signaled that the great range and accuracy of rifled cannons had made brick masonry forts forever obsolete. As the war progressed, other brick masonry forts in their turn succumbed to Union rifled cannon. None was more thoroughly ruined than Fort Sumter in Charleston harbor. (If you’ve been to Fort Sumter National Monument, you know what I mean.) Long before the Civil War ended, Union warships were firing at the place more or less to make the rubble bounce.

This was certainly not the case at Fort Pulaski. Its quick surrender left it in surprisingly good condition. Much of the damage was subsequently repaired – you can see where the patches were made – but many scars from the bombardment are still visible on the fort’s walls (see the accompanying photo).

Post script: The winner gets to make the rules. After the fort’s capture, Union Major General David Hunter, an ardent abolitionist, ordered the release of area slaves. Some of these freed slaves were recruited into the Union army and organized into the First South Carolina Colored Regiment