[1]: 48  The much larger Mexican force defeated the Americans in the opening of hostilities, and was the primary justification for U.S. President James K. Polk's call to Congress to declare war.

[1]: 47  Arista promptly ordered his subordinate, General Anastasio Torrejón, to cross the Rio Grande fourteen miles upstream at La Palangana.

[1]: 48  Ker found nothing but Thornton rode into an ambush and his 80-man force was quickly overwhelmed by Torrejon's 1,600, resulting in the capture of those not immediately killed.

[1]: 48  Thornton's guide brought news of the hostilities to Taylor and was followed by a cart from Torrejón containing six wounded Americans; the general stated that he had freed them as an act of mercy.

Opposition also existed in the United States, with one senator declaring that the affair had been "as much an act of aggression on our part as is a man's pointing a pistol at another's breast".