San Elizario was established in 1789 on the former site of Hacienda de Los Tiburcios as a Spanish colonial fort known as the Presidio of San Elceario. The presidio was moved from its former location about 37 miles south in response to requests from settlers for military protection from Indian raids. It operated as a Spanish fort until 1814, when troops withdrew during the Mexican War for Independence. During its years as a part of Mexico, the Presidio of San Elceario, now San Elizario, was occupied periodically by Mexican troops, but a reduced military presence resulted in the fort's decline. American control of the area began in 1848 with the Treaty of Guadalupe Hidalgo, which established the Rio Grande as the border between the United States and Mexico. When El Paso County was organized in 1850, San Elizario was chosen as the first county seat and served in that role until 1873. In 1877 it was the scene of the crisis known as the Salt War, in which local businessmen attempted to control the salt market that had operated since colonial times. Although San Elizario was bypassed by the railroad and became a rural farming community, it remains an important element in the region's rich heritage.