Fort Brown (originally Fort Texas) was a military post of the United States Army in Cameron County, Texas, during the latter half of the 19th century and the early part of the 20th century. Established in 1846, it was the first US Army military outpost of the recently annexed state. Confederate Army troops stationed there saw action during the American Civil War. In the early 20th century, it was garrisoned in relation to military activity over border conflicts with Mexico. Surviving elements of the fort were designated as a National Historic Landmark in 1960. Early years In 1846, Captain Joseph K. Mansfield directed the construction of a star-shaped earthwork for 800 men called "Fort Texas" on the northern side of the Rio Grande, "by the order from General [Zachary] Taylor to command the city of Matamoros" south of the river. The next year, the fort was besieged during the opening of the Mexican–American War. During the Siege of Fort Texas, two Americans were killed, including Major Jacob Brown and George Oakes Stevens (of Vermont) of the 2nd Dragoons. In honor of the fallen major, General Taylor renamed the post as Fort Brown. In 1849, the city of Brownsville, Texas, was established not far from the fort's grounds, after the United States had acquired Texas following the war. Cortina While in command at the fort, Major Samuel P. Heintzelman coordinated with John Salmon Ford in the Cortina Troubles, culminating in the Battle of Rio Grande City in 1859. Civil War In 1861, Confederate Col. John "Rip" Ford occupied the fort, with a garrison there until 1863. The Confederate forces were finally driven out by Union forces under General Nathaniel P. Banks, who had his troops camped in tents erected at the fort site. This Union occupation ended in 1864, when Confederate forces under General James E. Slaughter and Colonel Ford took control of the area. They held the post until the end of the war, when it was occupied again by Union forces under General Egbert Brown. Postbellum From 1867–1869, a permanent US Army fort was constructed under the supervision of Capt. William A. Wainwright. In 1882, Dr. William Crawford Gorgas was assigned to the hospital at Fort Brown during the height of a yellow fever outbreak. Using Fort Brown as his base of operations, Gorgas studied the disease for several years. He was sent to Cuba during the Spanish–American War.