Battle of Palo Alto Summary

  • Last updated on November 10, 2022

This battle, which preceded the formal beginning of the Mexican War, saw the shedding of blood on soil claimed by both nations. A chance for peaceful reconciliation was lost between the United States and Mexico over the issue of the annexation of Texas and the purchase of other western Mexican lands by the United States.

Summary of Event

Attempts by the administration of President James Polk to purchase Texas for annexation Texas;annexation by United States into the union were staunchly rebuffed by Mexico, which had seen Texas as a rebellious province since its declared independence in 1836. Failing to persuade Mexico peacefully, Polk decided to use military pressure, and in May, 1845, he ordered Brigadier General Zachary Taylor to advance into Texas with troops. Taylor marched to the mouth of the Nueces River at Corpus Christi, where he established a supply base. A final rejection of Polk’s overtures by Mexico in January, 1846, prompted him to order Taylor to advance to the Rio Grande. Rio Grande;and Mexican War[Mexican War] Palo Alto, Battle of (1846) Texas;Battle of Palo Alto Mexican War (1846-1848);Battle of Palo Alto Taylor, Zachary [p]Taylor, Zachary;and Mexican War[Mexican War] Arista, Mariano Ringgold, Samuel Mexico;and United States[United States] [kw]Battle of Palo Alto (May 8, 1846) [kw]Palo Alto, Battle of (May 8, 1846) Palo Alto, Battle of (1846) Texas;Battle of Palo Alto Mexican War (1846-1848);Battle of Palo Alto Taylor, Zachary [p]Taylor, Zachary;and Mexican War[Mexican War] Arista, Mariano Ringgold, Samuel Mexico;and United States[United States] [g]United States;May 8, 1846: Battle of Palo Alto[2390] [g]Central America and the Caribbean;May 8, 1846: Battle of Palo Alto[2390] [g]Mexico;May 8, 1846: Battle of Palo Alto[2390] [c]Wars, uprisings, and civil unrest;May 8, 1846: Battle of Palo Alto[2390] [c]Diplomacy and international relations;May 8, 1846: Battle of Palo Alto[2390] [c]Expansion and land acquisition;May 8, 1846: Battle of Palo Alto[2390] Polk, James K. [p]Polk, James K.;and Mexican War[Mexican War]

On March 28, Taylor arrived on the Rio Grande opposite Matamoras with an army of some 3,350 men and constructed fortifications, dubbed Fort Texas. A supply base was established on the coast at Port Isabel, twenty-three miles to the northeast. Mexico saw this as an invasion, as it considered the Nueces River, 125 miles to the north, and not the Rio Grande, to be the real border between Texas and Mexico.

On April 24, General Mariano Arista arrived to take command of all local Mexican troops. The following day, Mexican cavalry, which had crossed the Rio Grande upriver of Matamoras, overwhelmed a patrol of U.S. dragoons and continued east to the Matamoras-Port Isabel road, thereby cutting Taylor’s line of supply. On May 1, this force joined the rest of Arista’s army as it crossed the Rio Grande. Realizing he had to reopen his line of supply, Taylor marched back to Point Isabel, leaving behind a garrison of five hundred men at Fort Texas under Major Jacob Brown. Arista marched north to a point on the road called Palo Alto, arriving too late to intercept Taylor.

The same day, Mexican batteries began bombarding Fort Texas from across the river while troops encircled it from the north; Brown’s garrison was now under siege. Meanwhile, Taylor’s force had arrived at Point Isabel and loaded supplies into 270 wagons. Encumbered by this supply train, Taylor began the return march to Fort Texas, and on May 8, he encountered Arista blocking his advance.

The prairie at Palo Alto, from Spanish for “tall timber,” took its name from the area’s stands of mesquite wood. Bordered to the north, west, and south by winding stream beds and a thick mesquite wood to the west, it was covered with a sharp cord grass that reached chest high. Arista deployed his force of 3,800 men in a line some 1,580 yards wide facing north. Anchoring his left, astride the Matamoras road, were four cavalry units under General Torrejon. Weapons;artillery Mexican War (1846-1848);artillery Seven infantry units with ten guns, mostly four-pounders, filled his line, while some light cavalry anchored his right. Taylor deployed his force of 2,228 troops facing Arista on a front roughly 2,250 yards wide. He deployed five infantry battalions in line with a battery of two heavy eighteen-pound guns to their front. In front of his right flank he placed Major Samuel Ringgold’s field battery of four six-pound guns, while in front of his left he placed Captain James Duncan’s Duncan, James field battery, also having four six-pounders.

These light field batteries, or flying artillery, had all-mounted crews and were trained to move, deploy, and fire quickly. One squadron of dragoons was held in reserve, while another supported the left flank and guarded the supply train, which had been brought up close behind the lines. Arista’s line overlapped that of Taylor, and he planned a double envelopment, but he held no reserve and his artillery was largely immobile. Approximately 1,250 yards separated the armies, between which were several ponds, which effectively bifurcated the battlefield and ensured all maneuvering would be on the flanks.

Contemporary Currier & Ives print of General Zachary Taylor commanding American troops at the Battle of Palo Alto.

(Library of Congress)

As Taylor’s troops advanced that afternoon, Mexican artillery opened a largely ineffective fire. Ringgold’s and Duncan’s light field batteries moved forward to respond. Both batteries moved to within seven hundred yards of the Mexican lines and began an accurate and destructive fire on the Mexican lines, concentrating on Arista’s left flank, where Taylor intended to make a bayonet charge to clear the road. Thinking it impractical for his infantry to advance through the tall grass under such terrible fire, Arista ordered Torrejon’s cavalry to turn the American right flank. The cavalry became disrupted in the stream beds and mesquite wood, however, and American infantry formed in square (a common defensive tactic against cavalry) and repulsed them.

After regrouping, the cavalry charged again, but Taylor had moved another infantry unit to his right along with two of Ringgold’s guns. Torrejon’s cavalry was driven back with considerable losses by late afternoon. About that time, smoldering artillery wads set the tall grass afire, causing a lull in the cannonade as smoke obscured the battlefield. Taylor moved his right flank forward along the road with the eighteen-pounders. Arista responded by pulling back his left flank and moving his right forward. The affect was to completely realign the battle lines, which now ran from southwest to northeast. The American guns resumed wreaking havoc on the Mexican lines, and Taylor ordered an assault on the Mexican left by a squadron of dragoons supported by infantry, but this was repulsed by concentrated Mexican artillery fire.

Attempting to take advantage of the disorder, Arista again ordered Torrejon’s cavalry to turn the American right flank, but fire from the American guns and infantry drove back the Mexican cavalry. The effectiveness of the U.S. light batteries made them primary targets for the Mexican guns, and Major Ringgold was badly wounded, dying two days later. Meanwhile, Duncan’s battery was pounding Arista’s right flank, which finally attacked. Advancing through the smoke with the setting sun in their eyes, Mexican infantry and cavalry were caught in enfilade by Duncan’s battery, and they were ravaged. Arista ordered another attack, but Duncan’s guns continued to sweep the Mexican columns, which broke and routed, collapsing Arista’s entire right flank.

An all-out advance by Taylor at this point might have swept the field, but darkness was falling and he worried about the security of his supply train. Arista’s guns had used up their available ammunition, and he ordered his battered army to fall back behind mesquite thickets under cover of darkness around 7 p.m. The Americans had suffered fifty casualties, fifteen of them fatal. Mexican fatalities were anywhere from three hundred to four hundred, with perhaps twice as many wounded.


Although the Battle of Palo Alto was a technical draw, the terribly lopsided casualties suffered by the Mexican army severely crippled their morale and primed them for a decisive defeat and rout the following day at Resaca de la Palma Resaca de la Palma, Battle of (1846) . The Mexican troops fled the north bank of the Rio Grande, the siege of Fort Texas (renamed Fort Brown in honor of Major Brown, who was killed during the siege) was lifted, and the main U.S. supply base at Port Isabel was secured.

On May 13, Congress Congress, U.S.;and Mexican War[Mexican War] formally declared war, with Polk stating that “American blood” had been shed on “American soil.” Much of the American public was elated by the news of the victory, which seemed to affirm President Polk’s policy of provoking war with Mexico. Staffed by a West Point-educated professional officer cadre, the small but well-trained U.S. regular army proved its skill and mettle in battle, especially the well served and aggressively employed “flying artillery,” which proved decisive.

Samuel Ringgold became a national war hero, and his death was regarded as an example of gallant, patriotic sacrifice. The way was opened for an American invasion of northern Mexico. Taylor’s army was reinforced over the summer, and the following September it moved south and captured the strategic city of Monterrey. Palo Alto gave U.S. troops an initial boost in morale, creating a momentum they never lost, and it proved to be a harbinger of the future course of the war, which would be a humiliating disaster for Mexico.

Further Reading
  • citation-type="booksimple"

    xlink:type="simple">Dillon, Lester R., Jr. American Artillery in the Mexican War, 1846-1847. Austin, Tex.: Presidial Press, 1975. A study of the ordnance, doctrine, and tactics of the branch of service that was so decisive in the battle and the war. Includes an account of the Battle of Palo Alto.
  • citation-type="booksimple"

    xlink:type="simple">Eisenhower, John S. D. So Far from God: The U.S. War with Mexico, 1846-1848. New York: Random House, 1989. One of the most accessible and balanced narratives of the war, including the opening battles.
  • citation-type="booksimple"

    xlink:type="simple">Haecker, Charles M., and Jeffrey G. Mauck. On the Prairie of Palo Alto: Historical Archeology of the U.S.-Mexican War Battlefield. College Station: Texas A&M Press, 1997. A detailed analysis of the battle, with scientific data that has altered long-established beliefs about the positions and movements of the armies at Palo Alto.
  • citation-type="booksimple"

    xlink:type="simple">Mahin, Dean B. Olive Branch and Sword: The United States and Mexico, 1845-1848. Jefferson, N.C.: McFarland, 1997. A diplomatic history of the Mexican War that concentrates on the policies of the Polk administration.
  • citation-type="booksimple"

    xlink:type="simple">Winders, Richard Bruce. Mr. Polk’s Army: American Military Experience in the Mexican War. Texas A&M University Military History 51. College Station: Texas A&M Press, 2001. Presents cultural, social, and political analyses of the U.S. military experience drawn from exhaustive primary sources. Includes accounts of the Battle of Palo Alto.

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Categories: History