Battle of Churubusco
In the Mexican–American War, Gladden was a major and then, as lieutenant colonel, commander of the Palmetto Regiment of South Carolina volunteers. After the death of its colonel and lieutenant-colonel while storming the Mexican works at the Battle of Churubusco, Gladden became lieutenant colonel and commander of the regiment. He led the Palmetto Regiment in the assault upon the Belen Gate at the Battle of Mexico City, where he also was severely wounded.