On the 30th of July, 1845, the secretary of war, Mr. Marcy, declared to him that "the Rio Grande is claimed to be the boundary between the two countries, and up to this boundary you are to extend your protection, only excepting any posts on the eastern side thereof which are in the actual occupancy of Mexican forces, or Mexican settlements over which the republic of Texas did not exercise jurisdiction at the period of annexation, or shortly before that event. It is expected that, in selecting the establishment for your troops, you will approach as near the boundary line—the Rio Grande—as prudence will dictate. With this view, the President desires that your position, for a part of your forces, at least, should be west of the river Nueces."
This, and even more forcible language, was repeated in letters from the same source on the 23d and 30th of August, and on the 16th of October, 1845. In the last letter the secretary of war states distinctly that the western boundary of Texas is the Rio Grande. See Senate doc. No. 337, 29th cong. 1st sess. pp. 75, 77, 80, 81, 82.
[82] That this was General Taylor's view of the question is proved by a remark in his letter to General Ampudia on the 12th of April, 1846, on being warned by that officer to break up his camp and to retire to the other bank of the Nueces. General Taylor says: I need hardly advise you that charged as I am, in only a military capacity, with the performance of specific duties, I cannot enter into a discussion of the international question involved in the advance of the American army.—id. p. 124.
[83] See Senate Doc. No. 337, 29th cong. 1st sess. p. 99.
[84] Id. p. 75.
[85] Id. p. 82.
[86] American State papers, vol. 4, p. 468.
[87] Id. vol. 2, p. 662.
[88] As it may be important that the reader should understand the title to Louisiana under which the boundary of the Rio Grande was claimed, the following is a summary of its history. Louisiana originally belonged to France, but by a secret compact between that country and Spain in 1762, and by treaties, in the following year, between France, Spain, and England, the French dominion was extinguished on all the continent of America. In consequence of the treaty between this country and England in 1783, the Mississippi became the western boundary of the United States from its source to the 31° of north latitude, and thence, on the same parallel to the St. Mary's. France, it will be remembered, always had claimed dominion in Louisiana to the Rio Bravo or Rio Grande, by virtue
1st. Of the discovery of the Mississippi from near its source to the ocean.