Vidal's Cavalry Company was organized by A. I. Vidal near Brownsville, Texas, in October, 1863. It was made up of Mexicans and totaled about 60 men. The unit was assigned to H. P. Bee's command, Trans-Mississippi Department, and served at the mouth of the Rio Grande. On October 28, Vidal and his men turned traitor to the Confederate States. They killed other Confederates, stole weapons and supplies, and rode south across the Rio Grande. Mexican troops captured about 20 men and returned them to Confederate authorities. Vidal and the rest of his command joined the U.S. Army and became known as Vidal's Partisan Rangers Cavalry Company. Captain Adrian J. Vidal was in command.