In the fall of 1845 the administration no longer believed that an invasion of Texas by Mexico was imminent. Nonetheless, the administration again urged Taylor to take up a position near the western boundary of Texas (the Rio Grande) as soon as possible, and monitor any activity by Mexican troops or Comanches. It further asked Taylor for more detailed topographical information of the coastline.
WAR DEPARTMENT,
Washington, October 16, 1845.
SIR: The information which we have here, renders it probable that no serious attempts will, at present, be made by Mexico to invade Texas, although she continues to threaten incursions. Previous instructions will have put you in possession of the views of the government of the United States, not only as to the extent of its territorial claims, but of its determination to assert them. In carrying out these instructions, you will be left very much to your own judgment, by reason of your superior knowledge of localities, and the earlier notice you may receive of the probable views of Mexico, and the movements of her troops.
On the supposition that no active operations on your part will be required during the approaching winter, an important question to be decided is the position or positions to be occupied by your forces. This must be determined mainly with reference to the objects for which the army under your command was sent into Texas. You will approach as near the western boundary of Texas (the Rio Grande) as circumstances will permit; having reference to reasonable security; to accommodations for putting your troops into winter huts, if deemed necessary; to the facility and certainty of procuring or receiving supplies; and to checking any attempted incursions by the Mexican forces or the Indian tribes. Ought your present position to be changed? the forces which are, or soon will be, assembled under your command, be kept together or divided? and, if divided, what positions are to be taken, and how are they to be divided? These are questions which must be in a measure left to your judgment, or at least, the decision upon them here, if there be time, will be influenced in no inconsiderable degree by the information and views which you may furnish the department. You need not, therefore, wait for directions from Washington, to carry out what you may deem proper to be done. Upon all the points above enumerated, and others not suggested, your reports and views in full are desired, not only with reference to the continuance of the present aspect of affairs between the United States and Mexico, but in the contingency of your selecting, or being directed to take, a position on the banks of the Rio Grande near its mouth, or places above, or even in the event of open hostilities. It is expected that the officers of the engineer and topographical corps, who have been sent into Texas, will examine, as far as practicable, under your direction, the country, with a view to selecting eligible positions for permanent or temporary occupation, for depots of supplies, arms, and munitions of war. It is extremely desirable that the sea coast¡ or at least that part of it which will be likely to be visited by our vessels in aid of any contemplated military operations, should be better known here than it now is; as well as the character of the several rivers which may present obstacles to the movements of our forces, or furnish facilities for transporting supplies. You are requested to avail yourself of all proper occasions, and employ the means you possess, to collect information in regard to all these matters, and forward it to this department.
Very respectfully, your obedient servant,
WM. L. MARCY, Secretary of War.
Brigadier General Z. TAYLOR,
Commanding army of occupation in Texas.
