Brazos Santiago Pass, to south of this spot, was important Confederate harbor-entry during the Civil War. On island across the pass were fort and town of Brazos Santiago, where on Feb. 21, 1861, Texas troops under Col. John S. Ford captured the U. S. depot with mortars, siege guns and ordnance. A Confederate battery was then set up. In March 1861, off the bar, on U. S. S. "Daniel Webster", E. B. Nichols and Maj. Fitzjohn Porter, acting for Texas and the U. S. , arranged Federal evacuation of the Rio Grande. Blockade ships arrived Dec. 1861. Col. Ford shifted forces to Brownsville. Gen. J. B. Magruder, C. S. A. , ordered blasting of lighthouse north of pass, 1862. Trade vital to Confederacy plied from Cuba, Europe, Asia to Bagdad, Mexico, often actually slipping into Brazos Santiago Pass. Harbor sheltered blockade runners 1861-64.
On May 10, 1863, U. S. S. "Brooklyn" destroyed schooners in the harbor. Late 1863, French warships banned war material in Bagdad, and Mexican steam lighters ran guns from sea vessels into Brazos Santiago. Nov. 2, 1863, Gen. N. P. Banks landed U. S. Army here, took line of Rio Grande forts. Refortified Brazos Island and made it terminus for Army railroad to Rancho Blanco on Rio Grande. When C. S. A. retook Rio Grande Line in 1864, Federals in Brownsville were thrown back to Brazos Island. Col. Theodore H. Barrett, with troops from here, marching on Brownsville in May 1865, was confronted by Col. Ford's Confederates at Palmito Hill and fought last engagement of the Civil War.