A detail view of the forward wall of the Citadel, at old Fort Pike, a Second System fortress erected to protect the Rigolets Pass between Lakes Ponchratrain and Bourne, just north of New Orleans. The Citadel served as both a barracks and as a last line of defense. Were invaders able to get over the fort's walls, the garrison could withdraw to the Citadel and continue to fire upon the enemy through the rifle vents in the Citadel's walls. Fort Pike was initially occupied by a Confederate garrison at the outset of the Civil War, but when Admiral David Farragut's successful incursions up the Mississippi River drove Southern forces from New Orleans, Union troops replaced the Confederate garrison. It is said that Fort Pike was also used as a holding facility for Seminole indian prisoners.
