the forcing a passage would become almost impracticable. Here again iron-clad vessels would be very useful for reconnoitering or destroying rafts.
Would it be prudent, however, supposing these works to be at all formidably armed, to force a passage, leaving them behind intact, while the fleet advanced on New Orleans? I think not, unless perchance in conjunction with an attack to be made on the city by a large land force from Lake Borgne or Pontchartrain; bit it is as hard to get a land force from these lakes as to take Forts Jackson and Philip. A fleet cannot maintain itself long above those works unless the city of New Orleans is captured and held by us. If it should meet damage in passing and serious reverses higher up, it would have to pass the gauntlet again in retiring and our loss become very great.
On the other hand, to take these works is to open the navigation of the river up to Memphis to us and to lay open the whole country (as well as to take New Orleans) to the enterprises of our fleets.
It is the key to all the rest, and I believe it is an undertaking which requires as little risk, as small an outfit, as any there can be designed in this quarter.
Before indicating how I would operate against these works I will make a few remarks how I would operate against these works I will make a few remarks about the topography. It is to be regretted that with all the surveys we have made and the length of time our officers (myself among others) have been connected with this place we have such uncertain information as to the exact character of the ground surrounding these works. I state the character to the best of my ability. The river banks everywhere, even to the mouth, I believe furnish a margin of firm ground, only overflowed in the higher stages of the river. (Unfortunately during the months of March, April, May, and June we are certain to find the river pretty well up to high-water stage.) This strip of firm ground from Fort Jackson down for about a mile is from 300 to 400 yards, and except where cleared, to open the fire of the guns, is wooded with cottonwood and willow, the latter perhaps from 1 to 2 feet diameter.
Extending 450 or 500 yards below Fort Jackson is old levee (made at the time of the commencement of the work),having a return or below running back to the swamp. (See large map.) This return is near 400 yards long. It serves to protect the rear of the fort from the back-water of overflow. This levee was repaired, I think, under my directions. It is quiet likely that it has been neglected since, and that there are breaches in it, but these could be easily repaired, and the levee would keep the space behind pretty dry, even at high water. The level of the natural soil about Fort Jackson near the river is, say, a little over 3 feet above ordinary low water. The ordinary rise of river is, say, 5 feet, overtopping the banks, say, 2 feet.
The fort levee proper inclosed the work and grounds (see map), passing within about 100 yards of the northern bastion salient, 150 from the two eastern, and 300 (about) from the two western bastion salients.
Above Fort Jackson the high ground extends farther back (say one-half mile); is leaved, and might ne kept dry at all stages. (If an attack on these works was feared and the river up probably all the levees would be cut, but they are easily repaired.)
Next above Bayou Denis is cleared and cultivated ground, and next above Bayou des Liards is the Burnt Settlement, a hamlet of neat residences, with rice fields and orange groves.
27 R R - VOL XV