On May 13, 1865, more than a month after the surrender of Gen. Robert E. Lee, the last land action of the Civil War took place at Palmito Ranch near Brownsville. Early in the war the Union army had briefly occupied Brownsville but had been unable to hold the city. They established a base at Brazos Santiago on Brazos Island from which to blockade the Rio Grande and Brownsville. They were, however, unable to blockade the Mexican (and technically neutral) port of Bagdad, just below the river. The Confederates landed supplies at Bagdad and then transported them twenty-five miles inland to Matamoros to be shipped across the Rio Grande into Brownsville.
In February 1865 the Union commander at Brazos Island, Col. Theodore H. Barrett, reported to his superiors that his base was secure from attack and that with permission he could take Brownsville. The superiors refused to sanction the attack. Instead, Maj. Gen. Lewis Wallace sought and received Lt. Gen. Ulysses S. Grant's permission to meet the Confederate commanders of the Brownsville area, Brig. Gen. James E. Slaughter, commander of the Western Sub-District of Texas, and Col. John Salmon (Rip) Ford, commander of the southern division of Slaughter's command, at Port Isabel on March 11, 1865, in hopes of arranging a separate peace. Wallace promised no retaliation against former Confederates so long as they took an oath of allegiance to the United States. Anyone who preferred to leave the country would be given time to gather up property and family before doing so. An informal truce was arranged while Ford and Slaughter sent Wallace's proposals up the chain of command, and Wallace informed Grant that the rebels in Texas would soon be surrendering. Slaughter's superior in Houston, however, Maj. Gen. John G. Walker, denounced Wallace's terms and wrote a stinging letter to Slaughter for having listened to them in the first place. The commander of the Confederate Trans-Mississippi Department, Lt. Gen. Edmund Kirby Smith, was not ready to abandon the cause either. On May 9, 1865, he told the governors of the western Confederate states that despite Lee's surrender, his own army remained, and he proposed to continue the fight.
The Confederates in Texas were aware of the fate of the Confederacy's eastern armies. On May 1, 1865, a passenger on a steamer heading up the Rio Grande towards Brownsville tossed a copy of the New Orleans Times to some Confederates at Palmito Ranch. The paper contained the news of Lee's surrender, Lincoln's death, and the surrender negotiations between Johnston and Sherman. Within the next ten days several hundred rebels left the army and went home. Those who remained were as resolute as their commanders to continue the fight in Texas. The federals, meanwhile, had received an erroneous report that the southerners were preparing to evacuate Brownsville and move east of Corpus Christi. In light of this intelligence Colonel Barrett ordered 250 men of the Sixty-second United States Colored Infantry and fifty men of the Second Texas United States Cavalry (dismounted) to cross to the mainland from Brazos Island at Boca Chica Pass to occupy Brownsville. Carrying five days' rations and 100 rounds of ammunition per man, the Union troops crossed over to the coast at 9:30 P.M. on May 11, 1865. Under the command of Lt. Col. David Branson, this detachment marched all night and reached White's Ranch at daybreak. There Branson's men halted and tried to conceal themselves in a thicket along the Rio Grande. The camp was spotted by "civilians" (probably Confederate soldiers) on the Mexican side of the river. Realizing that any hope of surprising the Confederates was lost, Branson immediately resumed his march toward Brownsville.
At Palmito Ranch the federals encountered Capt. W. N. Robinson's 190-man company of Lt. Col. George H. Giddings's Texas Cavalry Battalion, which skirmished briefly with the Union force before retiring. The federals, too, fell back to a hill overlooking the ranch to rest and cook dinner. Camping for the night, the Union troops remained undisturbed until 3:00 A.M., when Robinson's company reappeared. Colonel Ford, at Fort Brown, had ordered Robinson to maintain contact with Branson's column and promised to reinforce him as soon as possible. Under pressure from Robinson, the federals fell back to White's Ranch, from where Branson sent a courier to Brazos Santiago asking Colonel Barrett for reinforcements. Barrett himself arrived at 5:00 A.M. on May 13, 1865, with 200 men of the Thirty-fourth Indiana Infantry, bringing the Union strength up to 500 officers and men. Under Barrett's command the column moved on Palmito Ranch once more, and a "sharp engagement" took place in a thicket along the riverbank between Barrett's 500 troops and Robinson's 190 Confederates. The outnumbered but persistent southerners were soon pushed back across an open prairie and beyond sight, while the exhausted federals paused on a small hill about a mile west of Palmito Ranch. At three that afternoon, Colonel Ford arrived to reinforce Robinson with 300 men from his own Second Texas Cavalry, Col. Santos Benavides's Texas Cavalry Regiment, and additional companies from Giddings's battalion, as well as a six-gun battery of field artillery under the command of Capt. O. G. Jones.
With mounted cavalry and artillery, Ford had the perfect force to deal with Barrett's infantry on the flat, open land around Palmito Ranch. Hidden by a group of small trees, Ford's men formed their line of battle. At 4:00 P.M. Jones's guns began to fire. After a brief bombardment, Robinson's men attacked the Union left near the river, while two other companies of Giddings's battalion struck its right. At the same time, the rest of Ford's men charged the enemy center. The southern assault came as a great surprise, and the Union line rapidly fell apart. Barrett later reported that "Having no artillery to oppose the enemy's six twelve-pounder field pieces our position became untenable. We therefore fell back fighting." Ford remembered it differently when he wrote in his memoirs that Barrett "seemed to have lost his presence of mind" and to have led his troops off the field in a "rather confused manner." Forty-six men of the Thirty-fourth Indiana were put out as skirmishers and left to be captured as the federals fell back toward Brazos Island. Only by deploying 140 men of the Sixty-second Colored in a line running from the Rio Grande to three-quarters of a mile inland did the Union troops slow the Confederate attack enough to allow the northerners to get away. Ford wrote that the battle from its beginning had been "a run," and demonstrated "how fast demoralized men could get over ground." The Confederates chased the federals for seven miles to Brazos Island. There the routed Union troops were met by reinforcements, and Ford's men ceased their attack. "Boys, we have done finely," said Ford. "We will let well enough alone, and retire." The action had lasted a total of four hours. Confederate casualties were a few dozen wounded. The federals lost 111 men and four officers captured, and thirty men wounded or killed. Ironically, at the same time as the battle of Palmito Ranch, the Confederate governors of Arkansas, Louisiana, Missouri, and Texas were authorizing Kirby Smith to disband his armies and end the war. A few days later federal officers from Brazos Santiago visited Brownsville to arrange a truce with General Slaughter and Colonel Ford.