Fort Fillmore, Where the Union Surrendered the Rio Grande

Fort Fillmore sat on the west bank of the Rio Grande about six miles south of Mesilla, established in eighteen fifty-one to protect travelers on the Chihuahua Trail and El Camino Real. It was already a troubled post, short on water after the river shifted away from it, when the Civil War arrived. In July of eighteen sixty-one, Confederate forces under Lieutenant Colonel John Baylor marched north from Texas and demanded the fort's surrender.

Major Isaac Lynde, commanding only several hundred poorly supplied Union soldiers, attempted to retreat northward but was overtaken near San Augustine Springs and surrendered his entire command without a major engagement. It was one of the most ignominious Union capitulations of the war. The Confederates held the Mesilla Valley for about a year before a California Column of Union troops retook New Mexico in eighteen sixty-two.

Almost nothing of the original fort remains above ground today.