The History of American Military. Richard W. Stewart
the open prairie a long dark line with bayonets and lances glistening in the sun. It was the Mexican Army.
Battles of Palo Alto and Resaca de la Palma
Containing some of the best regular units in the Mexican Army, General Arista’s forces barring the road to Fort Texas stretched out on a front a mile long and were about 4,000 strong. Taylor, who had placed part of his force in the rear to guard the supply wagons, was outnumbered at least two to one; and in terrain that favored cavalry, Arista’s cavalry overwhelmingly outnumbered Taylor’s dragoons. On the plus side for the Americans, their artillery was superior. Also, among Taylor’s junior officers were a number of capable West Point graduates, notably 2d Lt. George C. Meade and 2d Lt. Ulysses S. Grant, who were to become famous in the Civil War.
On the advice of the young West Pointers on his staff, Taylor emplaced his two 18-lb. iron siege guns in the center of his line and blasted the advancing Mexicans with canister. His field artillery— bronze 6-lb. guns firing solid shot and 12-lb. howitzers firing shell, in quick-moving attacks threw back Arista’s flanks. The Mexicans were using old-fashioned bronze 4-pounders and 8-pounders that fired solid shot and had such short ranges that their fire did little damage. During the battle Lieutenant Grant saw their cannon balls striking the ground before they reached the American troops and ricocheting so slowly that the men could dodge them.
During the afternoon a gun wad set the dry grass afire, causing the battle to be suspended for nearly an hour. After it resumed, the Mexicans fell back rapidly. By nightfall, when both armies went into bivouac, Mexican casualties, caused mostly by cannon fire, numbered 320 killed and 380 wounded. Taylor lost only 9 men killed and 47 wounded. One of the mortally wounded was his brilliant artilleryman, Major Ringgold.
At daybreak the Americans saw the Mexicans in full retreat. Taylor decided to pursue but did not begin his advance until afternoon, spending the morning erecting defenses around his wagon train, which he intended to leave behind. About two o’clock he reached Resaca de la Palma, a dry riverbed about five miles from Palo Alto. There, his scouts reported that the Mexicans had taken advantage of his delay to entrench themselves strongly a short distance down the road in a similar shallow ravine known as Resaca de la Guerra, whose banks formed a natural breastwork. Narrow ponds and thick chaparral protected their flanks.
Taylor sent forward his flying artillery, now commanded by Lt. Randolph Ridgely. Stopped by a Mexican battery, Ridgely sent back for help; Taylor ordered in a detachment of dragoons under Capt. Charles A. May. The dragoons overran the Mexican guns but on their return were caught in infantry crossfire from the thickets and could not prevent the enemy from recapturing the guns. American infantrymen later captured the pieces. Dense chaparral prevented Taylor from making full use of his artillery. The battle of Resaca de la Palma was an infantry battle of small-unit actions and close-in, hand-to-hand fighting.
The Mexicans, still demoralized by their defeat at Palo Alto and lacking effective leadership, gave up the fight and fled toward Matamoros. Their losses at Resaca de la Palma were later officially reported as 547 but may have been greater. The Americans lost 33 killed and 89 wounded. In the meantime, Fort Texas had been attacked by the Mexicans on May 3 and had withstood a two-day siege with the loss of only two men, one of them its commander for whom the fort was later renamed Fort Brown.
The panic-stricken Mexicans fleeing to Matamoros crossed the Rio Grande as best they could, some by boats, some by swimming. Many drowned; others were killed by the guns of Fort Texas. If Taylor’s regulars, flush with victory and yelling as they pursued the enemy, had been able to catch up with Arista, they could probably have taken his demoralized army, complete with guns and ammunition. But Taylor had failed to make any provision for crossing the Rio Grande. He blamed the War Department’s failure to provide him with pontoon equipment (developed during the Second Seminole War), which he had requested while he was still at Corpus Christi. Since that time, however, he had done nothing to acquire bridge materials or boats, although the West Pointers had urged him to do so. Lieutenant Meade reported that “the old gentleman would never listen or give it a moment’s attention.” Not until May 18, after Taylor had brought up some boats from Point Isabel, was he able to cross into Matamoros. By that time Arista’s army had pulled back into the interior to rest, recoup, and fight another day.
War Is Declared
On the evening of May 9, the day of the battle of Resaca de la Palma, President Polk received a message from the War Department that informed him of the attack on Captain Thornton’s detachment on April 25. Polk, already convinced by the breakdown in negotiations with Mexico that war was justified, immediately drafted a message declaring that a state of war existed between the United States and Mexico. Congress passed the declaration, and Polk signed it on May 13. Congress then appropriated $10 million and substantially increased the strength of the Army. (After the Second Seminole War the authorized strength had been cut from 12,500 to 8,500. This had been done by reducing the rank and file strength of the regiments, instead of eliminating units, thus firmly establishing the principle of an expansible Army.) Congress raised the authorized enlisted strength of a company from 64 to 100 men, bringing the rank and file up to 15,540, and added a regiment of mounted riflemen and a company of sappers, miners, and pontoniers (engineers for pontoon bridges). Also, the President was authorized to call for 50,000 volunteers for a term of one year or the duration of the war.
The President went into the war with one object clearly in view— to seize all of Mexico north of the Rio Grande and the Gila River and westward to the Pacific. After his discussions with Maj. Gen. Winfield Scott, the outlines of a three-pronged thrust emerged. (Map 21) General Taylor was to advance westward from Matamoros to the city of Monterrey, the key to further progress in northern Mexico. A second expedition under Brig. Gen. John E. Wool was to move from San Antonio to the remote city of Chihuahua in the west, an expedition later directed southward to Saltillo near Monterrey. A third prong under Col. Stephen W. Kearny was to start at Fort Leavenworth, capture Santa Fe and ultimately continue to San Diego on the coast of California. Part of Kearny’s forces under volunteer Col. Alexander W. Doniphan later marched south through El Paso to Chihuahua. Although small in numbers, only 1,600 strong, Kearny’s and Doniphan’s forces posed strategic threats to Mexico’s northern states.
Map 21
Polk was counting on “a brisk and a short war”; not until July did he and his Secretary of War, William L. Marcy, even begin to consider the possibility of an advance on Mexico City by landing a force on the Gulf of Mexico near Vera Cruz. General Scott was not so optimistic. He was more aware of the problems of supply, transportation, communications, and mobilization involved in operations against Mexico, a country with a population of 7 million and an army of about 30,000, many with experience gained by twenty years of intermittent revolution. Scott’s preparations seemed too slow to Polk. Ostensibly for that reason, but also because success in the field might make the politically motivated Scott a powerful contender for the Presidency, Polk decided not to give him command of the forces in the field. When news came of the victories at Palo Alto and Resaca de la Palma, Polk promoted Zachary Taylor to the brevet rank of major general and gave him command of the army in Mexico, risking the possibility that Taylor might also use a victory to vault into high political office.
Monterrey Campaign
Taylor’s plan was to move on Monterrey with about 6,000 men via Camargo, a small town on the San Juan River, a tributary of the Rio Grande about 130 miles upriver. From Camargo, where he intended to set up a supply base, a road led southwest about 125 miles to Monterrey in the foothills