From the Annals of the Loyal Unionists – In 1863, the First Texas Cavalry left New Orleans as part of a campaign to occupy south Texas and interfere with trade between the Confederacy and Mexico. The Rio Grande expedition landed on the south Texas coast on November 2 and occupied Brownsville four days later. The First Texas Cavalry included 16 officers and 205 enlisted men, but grew quickly added more than 100 new soldiers within a month. During this time the Second Texas Cavalry Regiment was formed at Brownsville. Both regiments left Texas in July 1864 for Louisiana. Two companies, however, of the First Texas Cavalry remained at Brownsville and did not rejoin their parent regiment until six months later. The First Texas was part of a little known Texas effort to support the Union. A total of 1,915 men from Texas served the Union. The Texas Union soldiers were primarily of Mexican heritage, German Unionists from the Hill Country or first generation Irish immigrants – all of whom were opposed to slavery.