In the spring of 1862, Union forces were poised to move down the strategically critical Mississippi River. Standing in the way of this Union advance, however, were the formidable fortifications at Island Number 10, pivotally positioned at the beginning of a double-bend in the great river. Bristling with more than 50 guns and supported by a Confederate riverboat squadron, this was an obstacle that Flag Officer Andrew Hull Foote believed too substantial for a naval frontal assault. Downstream, a Union Army force on the west bank of the river could cut Island Number 10’s supply lines and force a surrender if it could safely cross the river. But the needed naval escort was unavailable because all of the Navy’s ships were on the wrong (upstream) side of Island Number 10.
To break this impasse, Commander Henry Walke, captain of the ironclad USS Carondelet, volunteered to make a run, in the dark of night, past the fearsome fortifications. Walke prepared for the worst by augmenting the ship’s armor with heavy chains, piling wood on the decks to absorb plunging mortar shots, wrapping much of the pilothouse in a hawser cocoon, surrounding the boilers with cordwood, and securing a coal barge loaded with hay bales to her port side. Determined that his ship would not be captured, Walke armed the crew with pistols, cutlasses, and hand grenades and connected hoses to the boilers that could be used to scald any would-be boarders. To muffle the engine noise, piping was laid to carry escape steam to the paddlewheel housing instead of the stacks.
Just as the crescent moon slipped beneath the trees on the night of 4 April, the Carondelet took in all lines and commenced her stealth mission. At first, she was shrouded by the velvet black of the cloud-covered sky, but just as she neared the dreaded island, a furious storm erupted, illuminating the river (and what was on it) with great bolts of lightning accompanied by sonorous detonations of thunder. Torrents of rain fell and likely caused the Confederate lookouts to keep their heads down, for the only hostile fire came from above.
The Carondelet passed the first line of batteries unmolested, and it seemed as though she might make the entire passage undetected. But her fortunes changed as dry soot in her stacks ignited and long torches of flame climbed into the night sky. Shouted orders to elevate and fire could be heard emanating from the island, and soon the thump of artillery joined the celestial cacophony. Shells screamed overhead, and great geysers erupted from the river’s surface. In contrast to the Stygian chaos, a lone sailor kept his station on the bow, rhythmically throwing and retrieving his lead line and calling out soundings to ensure his ship did not run aground.
Miraculously, the Carondelet sustained no hits as she successfully ran the gauntlet and rendezvoused with her Army compatriots who boisterously cheered from the landing at New Madrid downstream. Two nights later, the USS Pittsburgh repeated the feat, and together the two ships escorted the Army across the river to the east bank where it soon forced the surrender of Island Number 10. The taking of this key position, along with the capture of New Orleans and eventually the fortress at Vicksburg, returned the “Father of Waters” to Northern control, effectively dividing the Confederacy and contributing significantly to the ultimate Union victory.