In May 1865, the Confederacy enjoyed one final huzzah on the banks of the Rio Grande. Less than a month after the Battle of Palmito Ranch, the war would be officially over and the Confederate States of America extinct. In this last engagement, primarily in defense of the Southern economy, Texans won the battle and the claim to the last land battle of the Civil War.

Protection of Texas ports and borders was of utmost concern to Confederate forces in the state. Early in the war, the Trans-Mississippi Department learned to rely on Texas ports as an outlet for European cotton sales as well as for the import of essential supplies. Mexico, in sympathy with the South, assisted the Confederate smuggling effort and, as a result, border towns prospered. When the Union gained control of the entire Texas coast by January 1864, even this trade route felt the squeeze of the blockade. But the occupation proved only temporary.

In the summer of 1864, Union troops began to withdraw from the Texas coast to focus more attention on campaigns to the east. The Federals retained coastal defenses only on Matagorda Peninsula and on the northern tip of Brazos Island at Brazos Santiago Depot near Fort Brown outside Brownsville. Light skirn1ishing occasionally occurred in the area, but Confederate international trade continued.

General Robert E. Lee surrendered his Army of Northern Virginia at Appomattox Court House on April 9, 1865. Though most Confederate troops surrendered their arms within the month, the Trans-Mississippi Department which included Texas, Arkansas and the Indian Territory (now Oklahoma) remained defiant despite knowledge of Lee's action.

Early in 1865, troops on the Texas coast reached a gentleman's agreement that there would be no point to continued hostilities. For that reason, it is unclear why Union Colonel Theodore H. Barrett ordered the attack on Fort Brown. One possibility is that Barrett, who lacked combat experience but had plenty of political aspirations, initiated the conflict in order to further his career. Another is that Barrett received a false report that Southerners were abandoning Brownsville to move eastward. Colonel Barrett himself never offered an explanation.

Whatever the inspiration, Barrett instructed Lieutenant Colonel David Branson to proceed toward the fort on the evening of May 11 with 250 men of the 62^nd U.S. Colored Troops (U.S.C.T.) Infantry and 50 men of the 2^nd Texas Volunteer Cavalry (unmounted). This Texas Cavalry was made up of Texas loyalists who had escaped to the north to join the Union ranks.

Forced to change routes by a fierce storm, the group crossed at Boca Chica and arrived at White's Ranch at 2:00 a.m. expecting to raid a Confederate outpost. Finding the site vacant, Branson decided to rest his troops in the vicinity and settled into a concealed area to spend the night. The next morning, people on the Mexican side of the river revealed the Federals' location to the Confederates. With the advantage of secrecy lost, the Union forces proceeded toward Fort Brown via Palmito Ranch.

En route, Union troops engaged in light skirmishing with about 190 Confederate cavalrymen known as Giddings’ Regiment led by Captain W. N. Robinson. The Federals gained ground against the smaller force, overrunning their camp at Palmito Ranch. The regiment halted the Union advance later in the day when joined by reinforcements. Branson's troops retired to White's Ranch for the night.

The next morning, Colonel Barrett joined Branson at White's Ranch with 200 men of the 34^th Indiana Volunteer Infantry under Lieutenant Colonel Robert G. Morrison. With added strength, the Federals, now under Barrett's command, pushed to a location beyond Palmito Ranch known as Tulosa Ranch. Participants later described the fighting here as "sharp" skirmishing.
 

About 4:00 in the afternoon on May 13, Colonel John S. "Rip" Ford arrived with 300 cavalry and a small artillery battery to assist the Confederates. Due to strong firepower to the front and right of his forces, Barrett found his position "untenable" and began an eight-mile retreat under the cover of a skirmish line. Ford and his Texans tailed the Union troops to Boca Chica where members of the 62^nd U.S.C.T. Infantry made a stand that allowed the bulk of the Federal troops to cross.

Colonel Ford called off the offensive in order to rest his men in expectation of a reinforced Federal attack. Ford's superior, General James E. Slaughter who had just arrived on the scene, ordered the attack to resume. However, Ford was adamant that his men were too tired to continue. He selected a camp about eight miles from the site of the last skirmishing. The counterattack never came.

In his account of events titled "The Last Battle - The Last Charge, and the Last Gun Fired in the War," participant Captain W. H. D. Carrington of Austin, Texas, recalled hearing the last shots of the Civil War. He reported that as evening fell, a shell from a nearby ship exploded between the two retreating armies. As a result, "a seven-teen-year-old trooper blazed away in the direction of the Enfield rifle, using a very profane expletive for so small a boy, causing a hearty laugh from a half score of his comrades."

According to both sides, the fight resulted in light casualties. Colonel Barrett reported the loss of four officers and 111 men. In his memoirs Colonel Ford recalled seven Confederates wounded and no one killed. Later assessments indicate that each army suffered roughly 140 killed, wounded or captured.

Confederate success in the Battle of Palmito Ranch only delayed the inevitable. The chaos of ultimate defeat soon gripped the state. Texas armies formally surrendered on May 26, 1865, followed by the entire Trans-Mississippi Department on June 2. The last in the long line of vicious battles between North and South was now history.