On the morning of 18 April, "Adolph Hugel" opened fire on Fort Jackson which, with Fort St. Philip across the river, protected New Orleans from seaborne attack. She and her sister schooner kept up the shelling for over two hours before ceasing fire at noon. Thereafter, Porter's mortars intermittently bombarded the Confederate fortifications. Their firing reached its peak in the pre-dawn darkness of the 24th when Farragut's fleet dashed upstream, passed the forts, and the next day took New Orleans. Four days later, the forts surrendered.