Some Civil War ships used cotton for armor.

Civil War battle ship

When the Civil War began in 1861, the United States Navy had just 90 warships. By the conflict’s end four years later, it had 626. Sixty-five of the ships were ironclads, which were the strongest seafaring vessels in the world at the time. But they were also expensive and made from scarce resources, which is why they accounted for such a small percentage of either side’s fleet. Hence the Confederacy’s eventual reliance on “cottonclads,” which were armored with 500-pound bales of cotton lining their sides. Because they were weaker than their iron counterparts, cottonclads would often steam at full speed toward their combatants as the cotton absorbed as much enemy gunfire as possible, then would attack once they were within firing range.

This proved more successful than you might expect. The Battle of Galveston began before dawn on January 1, 1863, with cottonclads playing a crucial role in the Confederate victory; the South held the Texas port for the rest of the war. Nevertheless, the Confederates were ultimately bested on the sea just as they were on land, failing to defend their rivers, coasts, and seas en route to their eventual surrender.

By the Numbers

Did you know?

Civil War generals were more likely to die in combat than privates.

We often think of the lowest-ranking soldiers as the most vulnerable when it comes to dying in combat, but that wasn’t the case during the Civil War. Generals and other high-ranking officers personally led their troops into battle during the internecine conflict (which remains the war with the most American fatalities by a considerable margin), making them 50% more likely to die in combat than privates. Six generals were killed and several more were wounded during the Battle of Antietam alone, the bloodiest one-day battle in American history. Perhaps unsurprisingly, generals have rarely entered the fray in subsequent wars.