With the outbreak of hostilities at Rancho de Carricitos, both U.S. and Mexican armies accepted war had begun. Neither side waited for a formal declaration of war. General Mariano Arista began shuttling troops across the Rio Grande to besiege the isolated Fort Texas.
The First Clash
General Taylor soon marched to assist his besieged men. After improving the defenses at his supply depot, known as Fort Polk, he set out on May 7th with 2,300 troops and 200 supply wagons to break the siege of Fort Texas. General Arista moved to block this advance. He positioned 3,200 troops across the Matamoros road where it crossed the broad prairie of Palo Alto. On the afternoon of May 8, 1846, he engaged the U.S. force in a fierce artillery battle—the first major clash of the war.
Across the Rio Grande
On May 18, 1846, Taylor's troops crossed the Rio Grande and entered the city of Matamoros. The occupation took place without a fight. Mexican forces had determined the city could not be defended and had withdrawn down the road leading to Monterrey. The lower Rio Grande Valley had been conceded to the U.S. Army.
Last updated: June 15, 2018