Despite the capture of their capital, the Mexicans refused to surrender. Belligerent civilians attacked army supply wagons and guerrilla fighters harassed American troops. In Mexico City and in Mexico's northern provinces hostile crowds staged demonstrations in the streets, and snipers fired shots and hurled stones and broken bottles from the tops of flat-roofed Mexican houses. Zachary Taylor issued the following proclamation in an attempt to impose order.
The Chief General of the American Forces
to the Inhabitants of Tamaulipas, Nuevo Leon and Coahuila.
When the American troops first crossed the frontier and entered the said districts, it was with the intention not to make war against the peaceful citizens of the country, but instead, with the aim of finding an honorable peace as quickly as possible....
The author [of this proclamation] was authorized by his government to make a levy or require tribute from the local communities in order to maintain his army. But disinclined to throw the heavy weight of the war on those who, with few exceptions, have manifested a neutral disposition, he has continued, from the beginning, to pay punctually and liberally for all the support that has been extracted in order to aid his troops.
He has made the greatest effort so that the war will not weigh heavily upon the citizens of those districts, and had hoped through these means to have enjoyed your confidence and assured your neutrality in the current dispute between his Government and that of Mexico. But with regret he is forced to say that his generosity has not been appreciated but has been met with acts of hostility.
Instead of continuing their business peacefully in their hearths, the citizens of the country have distributed arms in the roadways and encouraged ambushes [of U.S. forces]. Under the direction and with the support of the government, they have destroyed wagon trains and assassinated drivers in atrocious circumstances that are shameful to humanity.
The lives of those who have been so wickedly assassinated cannot be restored; but the author requires that the citizens of the country indemnify the losses caused by the destruction of the trains and the pillaging of their contents. Towards that end, an estimate will be made by the authorities of the entire loss. This loss must be made good in cash or in products of the country by the general community in the Districts of Tamaulipas and Nuevo Leon, each judicial district paying its fair share. And it is hoped that the rich will pay their proper share.
The author calls on all good citizens to remain absolutely neutral and not give aid to the partisans who infest the country with the sole object of killing and robbing.