Siege of Fort Texas The Siege of Fort Texas marked the beginning of active campaigning by the armies of the United States and Mexico during the Mexican - American War . The battle is sometimes called The Siege of Fort Brown , but this is not entirely accurate — the name Fort Brown was taken from Major Jacob Brown , who was one of the two Americans killed during the engagement . Major Jacob Brown should not to be confused with the War of 1812 hero Jacob Brown . Background . On March 27 , 1846 , troops under the command of General Zachary Taylor advanced to a north bank of the Rio Grande and began construction of an earthen star fort ress that they named Fort Taylor but was nicknamed " Fort Texas " . Mexican forces ambushed a troop of United States Cavalry , and then lay siege to the unfinished Fort Texas . The American garrison consisted of Major Brown ' s 7th Infantry , Captain Loud ' s artillery company of four 18 pounders , and Lieutenant Bragg ' s light artillery company of four more guns . Siege . Mexican General Mariano Arista began positioning his artillery , infantry and cavalry around the fort shortly after General Taylor departed on May 1 , 1846 . And , at 5 : 00 am on May 3 , 1846 , Mexican forces opened fire on the fort from guns placed directly across the Rio Grande at Matamoros . Troops of the United States 7th Infantry quickly responded with their own artillery . When additional cannon fire erupted from Mexican positions up and down the river ' s bank , fort commander Jacob Brown pointed his guns into the city of Matamoros . Fire continued on both sides until well into the night . In time , however , this artillery exchange gave way to a prolonged standoff . Despite the steady Mexican fire of May 3 , the earthen walls of the fort withstood the impacts well . Mexican leaders apparently acknowledged the lack of success and , in the ensuing days , firing on the fort diminished considerably . Apparently believing that a charge on the fort would produce heavy casualties in his own ranks , Mexican General Pedro de Ampudia instead settled in for a more traditional siege in the hope that General Arista ' s army could prevent American assistance from reaching the fort . The cannonade from within the fort declined as well . Realizing that the shots directed on Matamoros were having minimal effect , Major Brown called for a halt to firing . Over the next several days , the United States troops conserved their limited ammunition , offered only brief flurries of return fire and concentrated on shoring up the defenses of their post . Otherwise , the soldiers could do little but wait for General Taylor to march to the rescue . When that United States advance came , Mexican troops received orders to assist in efforts to halt the American Army . Although artillery continued a sporadic fire upon the fort , much of the Mexican infantry and cavalry ( Gen . Pedro Ampudia ' s Brigade ) surrounding the post moved forward to join the fighting at Palo Alto and Resaca de la Palma . The remaining Mexican force ( 1 , 540 men ) under Gen . Francisco Mejia consisted of Artillery ( 14 guns ) , the Matamoros National Grds . Battalion , and the Mexico , Puebla and Morelia Activos Battalions . The U . S . soldiers in Fort Texas first learned of the advance from the distant rumble of cannon fire at Palo Alto on May 8 . Additional sounds of battle revealed that fighting had reached Resaca de la Palma on May 9 . That afternoon , the sight of hundreds of Mexican soldiers rushing to crossing points on the Rio Grande indicated that Taylor ' s troops had been victorious . The American victory at Resaca de la Palma brought an end to the six - day bombardment of Fort Texas . Apparently concerned that the fire might strike their own retreating forces , Mexican gunners immediately halted their cannonade of the fort . The United States soldiers briefly fired upon the retreating Mexican troops , but they soon halted this activity when it appeared that they might strike their own compatriots , who followed in close pursuit . Though the confrontation at Fort Texas lasted six days , with periods of heavy cannon fire , casualties were remarkably low . Only two U . S . soldiers died in the bombardment , but that toll included the fort commander Jacob Brown . Major Brown was struck in the leg by a cannon ball on May 6 . He survived for several days only to die on May 9 , just hours before the siege ended . Despite his wound , Brown had helped maintain troop morale throughout the siege , thus contributing to the success of the defense of the Fort . Mexican leaders reported two killed and two wounded from American artillery fire during the siege . The effect of artillery fire on the civilian population of Matamoros is unknown . Aftermath . General Zachary Taylor came to the aid of the fort ' s defenders , which resulted in General Mariano Arista ' s order to position his forces on the nearby plain s of Palo Alto , thereby lifting the siege . The fort commander , Major Jacob Brown , was killed during the siege and Fort Texas was renamed after him . Laundress and cook Sarah Borginnes , who refused to take shelter during the siege but instead provided food and coffee to the American troops , was named " Heroine of Fort Brown " by the American newspapers .