Battle of Brownsville The Battle of Brownsville took place on November 2 – 6 , 1863 during the American Civil War . It was a successful effort on behalf of the Union Army to disrupt Confederate blockade runners along the Gulf Coast in Texas . The Union assault precipitated the capture of Matamoros by a force of Mexican patriots , led by exiled officers living in Brownsville . Background . During the first half of the war , the Union Navy had successfully blockaded many Southern ports along the Gulf Coast . Cotton trade was a major economic asset for Texas and the whole Confederacy . Initially cotton was transported to Brazos Santiago Pass at the delta of the Rio Grande and exported from Port Isabel . Union forces captured this port and trade was moved inland to Brownsville , Texas . From Brownsville goods were transported across the border to Matamoros and from there to neutral ports along the Mexican coast . The U . S . government was also anxious to show Union presence along the Mexican border since the French army had just invaded Mexico and installed Maximillian as emperor . Following the Union debacle at the second Battle of Sabine Pass , the U . S . government demanded General Nathaniel P . Banks , commanding the Department of the Gulf , to make another attempt at invading Texas . Battle . Nathaniel Banks assembled 6 , 000 soldiers from three brigades from Napoleon J . T . Dana ' s XIII Corps . The Confederate forces in the area were commanded by General Hamilton P . Bee . Bee ’ s forces consisted of a mere 4 companies from the 33rd Texas Cavalry under Colonel James Duff and another 2 companies of 3 month volunteers . All other Confederates along the coast had been called elsewhere in the wake of the Union attack at Sabine Pass . The total Confederate force amounted to roughly 150 men stationed at Fort Brown . One company of volunteers under Captain Adrian I . Vidal defected , killing a private and wounding another from the 33rd Texas . Banks landed the expedition at the mouth of the Rio Grande on November 2 , 1863 . Bee dispatched two companies of his cavalry to observe and report on the Union landing . Company A under Captain Richard Taylor arrived at the mouth of the Rio Grande while company F under Captain Henry Davis arrived at Point Isabel further north . On November 2 Captain Taylor informed General Bee the Union forces had landed cavalry while Bee made preparatory orders for the evacuation of Brownsville . Colonel William M . Dye ' s brigade led the Union advance . After chasing off Taylor ' s Confederate cavalry Dye ' s men entered the Brownsville around 10 : 00am on November 6 , 1863 . General Bee quickly ordered the evacuation of the city and abandoned Fort Brown . He personally supervised the burning of what military supplies and cotton he could . Inside the fort was 8 , 000 pounds of condemned explosives which caused a great explosion much to the terror of the local citizens . The Confederates ' destruction spread into the city while the soldiers resorted to looting prompting the local citizens into a degree of opposition . A local resident by the name of General José Maria Cobos was a Mexican general and refugee living in exile due to the recent French invasion . General Cobos received permission from the civilian authorities in Brownsville to organize a force to resist the looters and subdue the fires started by the Confederate evacuation . Around noon General Banks personally arrived in the city and by 4 : 00pm the remaining Union forces arrived . Colonel Dye was put in command of the post and the Union army encamped in the city , the army barracks at Fort Brown having been destroyed . The Union forces also captured a large supply of cotton left behind by the Confederates . Aftermath . The loss of Brownsville significantly disrupted Confederate cotton trade . The new trade route into Mexico lay roughly 300 miles northwest . Brownsville provided a base for further Union operations against Mustang Island and Fort Esperanza up the Texas coast . General Cobos took his vigilante force across the border and seized control of Matamoros . There he continued to be of concern to General Banks . Confederate forces made an attempt to recapture Brownsville in 1864 . Colonel John S . “ Rip ” Ford assembled a large force of cavalry . On July 30 , 1864 Ford found the new Union commander , Francis J . Herron , had already abandoned Brownsville and the Confederates were able to reoccupy the city . Forces . Union Department of the Gulf . Maj Gen Nathaniel P . Banks < br > < br > XIII Corps < br > Maj Gen Napoleon J . T . Dana Confederate District of Texas , New Mexico & Arizona . Maj Gen John B . Magruder 1st Division - Brigadier General Hamilton P . Bee