On the west side the highest land, except in a few places, is but little above the highest water.

Through this valley the river meanders in the most tortuous way, varying in direction to all points of the compass.

At places it runs to the very foot of the bluffs.

After leaving Memphis, there are no such highlands coming to the water's edge on the east shore until Vicksburg is reached.
The intervening land is cut up by bayous filled from the river in high water--many of them navigable for steamers.

All of them would be, except for overhanging trees, narrowness and tortuous course, making it impossible to turn the bends with vessels of any considerable length.
Marching across this country in the face of an enemy was impossible; navigating it proved equally impracticable.