We continued our journey again at daylight and by evening reached a point about ten miles above Vicksburg, where we drove our fleet ashore and remained on the boats all night. Fully seventy-five boats loaded with troops are assembled here, while the fleet of gunboats is lying in the river two miles below us. The country is very low here, the land on either side of the river being about twenty feet below the water in the river, which is kept within its banks by levees. The river is rising, and about three miles below us the levee on the Louisiana side has broken, and the land is being flooded.
Source: Alexander G. Downing, Edited by Olynthus B., Clark, Downing’s Civil War Diary, p. 96