The Battle of Palmito Ranch is considered the last major clash between Union and Confederate forces. The battle is widely considered to be a post-Civil War encounter as the Battle of Columbus in April of 1865 is considered to be the last battle of the war. The battle took place along the banks of the Rio Grande just about 12 miles east of Brownsville, Texas. Early in 1865, a gentlemen's agreement had been in place that there was no point in further hostilities between those forces stationed in south Texas. The exact causes of the battle are unknown and many theories have been proposed. Many believe that Union Colonel Theodore H. Barrett, lacking in any battle experience, desired a bit of battle glory before the end of the war. Others believe that Barrett needed horses for 300 dismounted cavalry in his brigade. Whatever the cause, Barrett instructed Lieutenant Colonel David Branson to attack the Confederate encampments commanded by Colonel John Salmon Ford at Palmito Ranches near Fort Brown.
Though the battle was considered a Confederate victory, there was little to no gain to the battle. Casualty counts are unreliable and are estimated at about 30 deaths on each side while about 100 Union forces were captured by Confederate forces. It is thought that many of the deaths were caused by drowning in the Rio Grande while others are attributed to French border guards on the Mexican side. Confederate forces in Texas formally surrendered on May 26, 1865.