My dear general:  The question of reconstruction in Louisiana, Mississippi, and Arkansas, will soon come up for decision of the Government, and not only the length of the war, but our ultimate and complete success, will depend upon its decision.  It is a difficult matter, but I believe it can be successfully solved, if the President will consult opinions of cool and discreet men, who are capable of looking at it in all its bearings and effects.  I think he is disposed to receive the advice of our generals who have been in these States, and know much more of their condition than gassy politicians in Congress.  General Banks has written pretty fully, on the subject.  I wrote to General Grant, immediately, after the fall of Vicksburg, for his views in regard to Mississippi, but he has not yet answered.

I wish you would consult with Grant, McPherson, and others of cool, good judgment, and write me your views fully, as I may wish to use them with the President.  You had better write me unofficially, and then your letter will not be put on file, and cannot hereafter be used against you.  You have been in Washington enough to know how every thing a man writes or says is picked up by his enemies and misconstrued.  With kind wishes for your further success,

I am yours truly,

H. W. HALLECK

[Private and Confidential.]

Headquarters, fifteenth army corps,
camp on big black, Mississippi, September 17 1863
H. W. Halleck, Commander-in-Chief, Washington, D. C.

Dear general:  I have received your letter of August 29th, and with pleasure confide to you fully my thoughts on the important matters you suggest, with absolute confidence that you will use what is valuable, and reject the useless or superfluous.

That part of the continent of North America known as Louisiana, Mississippi, and Arkansas, is in my judgment the key to the whole interior.  The valley of the Mississippi is America, and, although railroads have changed the economy of intercommunication, yet the water-channels still mark the lines of fertile land, and afford cheap carriage to the heavy products of it.

The inhabitants of the country on the Monongahela, the Illinois, the Minnesota, the Yellowstone, and Osage, are as directly concerned in the security of the Lower Mississippi as are those who dwell on its very banks in Louisiana; and now that the nation has recovered its possession, this generation of men will make a fearful mistake if they again commit its charge to a people liable to misuse their position, and assert, as was recently done, that, because they dwelt on the banks of this mighty stream, they had a right to control its navigation.