SOLDIERS! You have enlisted in a time of peace to serve in that army for a specific time; but your obligations never implied that you were bound to violate the laws of God, and the most sacred right of friends. The United States Government, contrary to the wishes of a majority of all honest and honorable Americans, has ordered you to take forcible posession of the territory of a friendly neighbor, who has never given her consent to such occupation. In other words, while the treaty of peace and commerce between Mexico and the United States is in full force, the United States, presuming on her strength and prosperity, and on our supposed imbecility and cowardice, attempts to make you the blind instruments of her unholy and mad ambition, and force you to appear as the hateful robbers of our dear homes, and the unprovoked violators of our dearest feelings as men and patriots. Such villainy and outrage I know is perfectly repugnant to the noble sentiments of any gentleman, and it is base and foul to rush you on to certain death, in order to aggrandise a few lawless individuals in defiance of the laws of God and man.
It is to no purpose if they tell you that the law for the annexation of Texas justifies your occupation of the Rio Bravo del Norte, for by this act they rob us of a great part of Tamaulipas, Coahuila, Chihuaha, and New Mexico; and it is barbarous to send a handful of men on such an errand against a powerful and warlike nation. Besides, most of you are Europeans, and we are declared friends of most of the nations of Europe. The North Americans are ambitious, overbearing, and insolent as a nation, and they will only make use of you as vile tools to carry out their abominable plans of pillage and rapine.
I warn you in the name of justice, honor, and your own interests and self-respect, to abandon their desperate and unholy cause, and become peaceful Mexican citizens. I guarantee you in such a case a half-section of land, or three hundred and twenty acres, to settle upon gratis. Be wise then, and just, and honorable, and take no part in murdering us who have no unkind feelings for you. Lands shall be given to officers, sergeants, and corporals, according to rank, privates receiving three hundred and twenty acres as stated.
If in time of action you wish to espouse our cause, throw away your arms and run to us, and we will embrace you as true friends and Christians. It is not decent or prudent to say more. But should any of you render important service to Mexico, you shall be accordingly considered and preferred.
Commander-in-Chief of the Mexican Army.
Memoirs of a Maryland Volunteer. War with Mexico in the years 1846-7-8 by John R. Kenly
J. B. Lippincott & Co., Philadelphia, 1873, pages 40-41