Battle of Palo Alto: Dates & Conflict:
The Battle of Palo Alto was fought on May 8, 1846, during the Mexican-American War (1846-1848).
Armies & Commanders
Battle of Palo Alto - Background:
Having won independence from Mexico in 1836, the Republic of Texas existed as independent state for several years though many of its residents favored joining the United States. The issue was of central importance during the election of 1844. That year, James K. Polk was elected to the presidency on a pro-Texas annexation platform. Acting quickly, his predecessor, John Tyler, initiated statehood proceedings in Congress before Polk took office. Texas officially joined the Union on December 29, 1845. In response to this action, Mexico threatened war, but was persuaded against it by the British and French.
After rebuffing an American offer to purchase the California and New Mexico Territories, tensions between the US and Mexico rose further in 1846, over a border dispute. Since its independence, Texas claimed the Rio Grande as its southern border, while Mexico claimed the Nueces River farther to the north. As the situation worsened, both sides sent troops to the area. Led by Brigadier General Zachary Taylor, an American Army of Occupation advanced into the disputed territory in March and constructed a supply base at Point Isabel and a fortification on the Rio Grande known as Fort Texas.
These actions were observed by the Mexicans who made no efforts to impede the Americans. On April 24, General Mariano Arista arrived to take command of the Mexican Army of the North. Possessing authorization to conduct a "defensive war," Arista made plans to cut Taylor off from Point Isabel. The next evening, while leading 70 US Dragoons to investigate a hacienda in the disputed territory between the rivers, Captain Seth Thornton stumbled upon a force of 2,000 Mexican soldiers. A fierce firefight ensued and 16 of Thornton’s men were killed before the remainder was forced to surrender.
Battle of Palo Alto - Moving to Battle:
Learning of this, Taylor sent a dispatch to Polk informing him that hostilities had commenced. Made aware of Arista's designs on Point Isabel, Taylor ensured that the defenses of Fort Texas were ready before withdrawing to cover his supplies. On May 3, Arista instructed elements of his army to open fire on Fort Texas, though he did not authorize an assault as he believed the American post would fall quickly. Able to hear the firing at Point Isabel, Taylor began planning to relieve the fort. Departing on May 7, Taylor's column included 270 wagons and two 18-pdr siege guns.
Alerted to Taylor's movement early on May 8, Arista moved to concentrate his army at Palo Alto in an effort to block the road from Point Isabel to Fort Texas. The field he chose was a two-mile wide plain covered in green saw grass. Deploying his infantry in a mile-wide line, with artillery interspersed, Arista positioned his cavalry on the flanks. Due to the length of the Mexican line, there was no reserve. Arriving at Palo Alto, Taylor allowed his men to refill their canteens at a nearby pond before forming into a half-mile long line opposite the Mexicans. This was complicated by the need to cover the wagons (Map).
The Battle of Palo Alto:
After scouting the Mexican line, Taylor ordered his artillery to soften Arista's position. Arista's guns opened fire but were plagued by poor powder and a lack of exploding rounds. The poor powder led to cannon balls reaching the American lines so slowly that soldiers were able to avoid them. Though intended as a preliminary movement, the actions of the American artillery became central to the battle. In the past, once artillery was emplaced, it was time consuming to move. To combat this, Major Samuel Ringgold of the 3rd US Artillery had developed a new tactic known as "flying artillery."
Utilizing light, mobile, bronze guns, Ringgold's highly-trained artillerymen were capable of deploying, firing several rounds, and shifting their position in short order. Riding out from the American lines, Ringgold's guns went into action delivering effective counter-battery fire as well as inflicting heavy losses on the Mexican infantry. Firing two to three rounds per minute, Ringgold's men dashed around the field for over an hour. When it became clear that Taylor was not moving to attack, Arista ordered Brigadier General Anastasio Torrejon's cavalry to attack the American right.
Slowed by heavy chaparral and unseen marshes, Torrejon's men were blocked by the 5th US Infantry. Forming a square, the infantrymen repulsed two Mexican charges. Bringing up guns to support a third, Torrejon's men were set upon by Ringgold's guns. Surging forward, the Mexicans were again turned back as the 3rd US Infantry joined the fray. By 4:00 PM, the fighting had set parts of the saw grass on fire leading to a heavy black smoke covering the field. During a pause in the fighting, Arista rotated his line from east-west to northeast-southwest. This was matched by Taylor.
Pushing forward his two 18-pdrs, Taylor knocked large holes in the Mexican lines before ordering a mixed force to attack the Mexican left. This thrust was blocked by Torrejon's bloodied horsemen. With his men calling for a general charge against the American line, Arista sent forward a force to turn the American left. This was met by Ringgold's guns and badly mauled. In this fighting, Ringgold was mortally wounded by a 6-pdr shot. Around 7:00 PM the fighting began to subside and Taylor ordered his men camp in line of battle. Through the night, the Mexicans gathered their wounded before departing the field after dawn.
Battle of Palo Alto - Aftermath
In the fighting at Palo Alto, Taylor lost 15 killed, 43 wounded, and 2 missing, while Arista suffered around 252 casualties. Allowing the Mexicans to depart unmolested, Taylor was aware that they still posed a significant threat. He was also expecting reinforcements to join his army. Moving out later in the day, he quickly encountered Arista at Resaca de la Palma. In the resulting battle, Taylor won another victory and forced the Mexicans to leave Texan soil. Occupying Matamoras on May 18, Taylor paused to await reinforcements before invading Mexico. To the north, news of the Thornton Affair reached Polk on May 9. Two days later, he asked Congress to declare war on Mexico. Congress agreed and declared war on May 13, unaware that two victories had already been won.