Third. At Louisville and Saint Louis there are probally fifty more boats of the largest size. These boats probably average double the tonnage of the others, being boats which cannot pass the locks at Louisville. These large boats taken together would probably carry nearly as many as all on the upper Ohio. I should think steam-boat accommodations could easily be had to move at one time 60,000 men. If it were a successful movement, of course the number might be indefinitely increased. In this estimate I include a considerable number of those which may not be fit for service. The packet-boats are not desirable, except in case of necessity, for the are constructed for a ligth business.
Fourth. There are in the course of the year about forty tow-boats (barges) in the Cincinnati trade, a large part of which can no doubt be had. There are also a number of coal barges, deep and strong, commontly carrying 4,000 bushels of coal. Enough barges could be obtained to carry heavy freight.
Fifth. The lower Ohio will probably have as much as five feet of water till the middle of July, the lowest water being generally in September and October. In the Mississippi River there is more water, so that from Cairo down there will be little or no difficulty. Some of the most dangerous places, however, are between Cairo and Memphis. I was at Memphis in the lowest water, and found it rather difficult navigation. Steam-boats of from 300 to 500 tons can go down easily. The Navigator or Pilot, which was formerly published, is discontinued, so that I cannot obtain you anything of that kind more aveilable than the result of my inquiries. It is possible I can get an old copy (which for purposes of river information is as good as a late one) and send you.
You are probably aware of the distinctive features of the town sites on the Mississippi. I consider Memphis the most valuable military point on the Mississippi between New Orleans and Cairo - as a defensible and as an aggressive point more valuable that either of them. It is not only one of the very few high and comparatively healthy places on the river, but in its relations to Arkansas, Mississippi, and Tennessee it has peculiar advantages. The recent construction of railroad centering there has quadrupled its advantages. You will observe that Memphis is the only point on the Mississippi where you can go directly to Charleston, New Orleans, and through to the valley of the Tennessee. I have passed through the whole valley of the Tennessee, including North Alabama, and the holding of Memphis by a military force is the holding of the whole country in the valley of the Tennessee. Any other point in the interior desirable to possess can be taken and held from that point till we reach the spurs of the Cumberland Mountains. When we reach the mountains we have a Union population, which only needs a little military aid to make themselves perfectly defensible. The lines of Virginia railroads turn on the axis of the valley railroad, which in succession take in Lynchburg, Bristol, Knoxville, Cleveland, Chattanooga, Tuscumbia, and Memphis. This great road is about 900 miles in length from Richmond to Memphis. If the Government then possess Virginia, garrisons stationed at Richmond, Lynchburg, Bristol, Knoxville, Chattanooga, and Memphis would command the whole of this immense railroad, silence all rebellion in Virginia, Tennessee, and North Alabama, and hold fast to Kentucky and to Missouri. From that moment the capture of all the cities and strong places in the cotton States becomes inevitable. In my opinion, the holding of these places would, in fact, terminate the war by the development of the Union strength and the organization of loyal State governments. The moment the overawing force of the rebel armies is