Fort Brown was established in 1846 by General Zachary Taylor's troops as an earthwork army post on the Rio Grande, built to defend the newly claimed U.S. border with Mexico and to protect the settlement that grew up around it into present-day Brownsville. For most of its active life the fort functioned as a working U.S. Army garrison, housing soldiers in barracks and support buildings, supplying border patrol and defense duties along the lower Rio Grande, and serving as a logistical post for regional military operations. It changed hands during the Civil War, was held at times by Confederate forces, and afterward returned to federal use; in the postwar decades it garrisoned Buffalo Soldier regiments, African American cavalry and infantry units who served there amid the era's segregation and were at the center of the controversial 1906 Brownsville Raid incident. The post remained an active military installation into the twentieth century before being decommissioned. Today the fort's grounds and several of its surviving historic buildings, including officers' quarters and other structures, have been incorporated into the campuses of Texas Southmost College and the University of Texas Rio Grande Valley in Brownsville, functioning as classrooms, administrative offices, and campus facilities. A portion of the site is preserved and interpreted through historical markers and a small museum, so the location now serves an educational and civic function rather than a military one.