Victory At Palo Alto
On May 8, 1846, General Zachary Taylor defeated a detachment of the Mexican army in a two-day battle at Palo Alto and Resaca de la Palma.
This victory forced Mexican troops across the Rio Grande River to Matamoros, protecting the newly annexed state of Texas from invasion. Five days later, the United States declared war against Mexico. At the direction of President James K. Polk, General Taylor led American forces on to brilliant victories at Monterrey and Buena Vista.
The Battle of Palo Alto was the first major battle of the Mexican-American War and was fought on May 8, 1846, on disputed ground five miles (8 km) from the modern-day city of Brownsville, Texas. A force of some 3,400 Mexican troops (a portion of the Army of The North) led by General Mariano Arista engaged a force of 2,400 United States troops — the so called US Army of Observation."