The Battle of Palmito Ranch, also known as the Battle of Palmito Hill, is considered by some criteria the final battle of the American Civil War. It was fought May 12 and 13, 1865, on the banks of the Rio Grande east of Brownsville, Texas, and a few miles from the seaport of Los Brazos de Santiago, at the southern tip of Texas. The battle took place more than a month after the surrender of the Army of Northern Virginia under Robert E. Lee to Union forces at Appomattox Court House, which had since been communicated to both commanders at Palmito. In the intervening weeks the Confederacy had collapsed entirely, so it could also be classified as a postwar action.
Union and Confederate forces in southern Texas had been observing an unofficial truce since the beginning of 1865, but Union Colonel Theodore H. Barrett, newly assigned to command an all-black unit and never having been involved in combat, ordered an attack on a Confederate camp near Fort Brown for unknown reasons.
Wikipedia https://en.wikipedia.org/wiki/Battle_of_Palmito_Ranch
Address 78521, United States
Coordinates 25°57'26.984" N -97°17'36.348" E