On Wednesday, April 22, 1863 in front of Vicksburg a Federal flotilla of six transports and twelve barges attempted to pass the city’s Confederate batteries. One transport and six of the barges were sunk by Vicksburg’s guns, but the remaining ships carried their precious supplies to Ulysses Grant’s troops below the city.
President Jefferson Davis by telegram advised Vicksburg’s commander, General John Pemberton, to float fire rafts down the Mississippi River when Union ships attempted to pass the city’s guns or to anchor them in the river on dark nights.
The use of fire rafts would make a water assault against the city prohibitively expensive for the attacking Union forces and thereby encourage Grant to assault the city’s substantial land defenses, which Davis believed impregnable to attack.