In the event of his failure to comply with these demands, Ampudia announced that "arms, and arms alone, must decide the question." According to the persistent claim of the Mexican Government, the Nueces River was the western boundary of Texas; and the territory between that river and the Rio Grande--a breadth of one hundred and fifty miles on the coast--was held by Mexico to be a part of her domain, and General Taylor consequently an invader of her soil.

No reply was made to Ampudia; and on the 24th of April General Arista, who had succeeded to the command of the Mexican army, advised General Taylor that "he considered hostilities commenced, and should prosecute them." BEGINNING OF MEXICAN WAR.
Directly after this notification was received, General Taylor dispatched a party of dragoons, sixty-three in number, officers and men, up the valley of the Rio Grande, to ascertain whether the Mexicans had crossed the river.

They encountered a force much larger than their own, and after a short engagement, in which some seventeen were killed and wounded, the Americans were surrounded, and compelled to surrender.

When intelligence of this affair reached the United States, the war-spirit rose high among the people.

"Our country has been invaded," and "American blood spilled on American soil," were the cries heard on every side.