In 1867 the United States Cavalry established Fort Concho along the banks of the river. The fort was built to protect frontier settlements, patrol and map the vast West Texas region, and quell hostile threats in the area. An enterprising merchant and businessman, Bart J. DeWitt, began a settlement across from the fort in 1870. Initially called Santa Angela in honor of his wife, the town grew into a community that provided services to Fort Concho. In 1881, residents unfamiliar with proper Spanish grammar corrupted the name to San Angela. The name was later changed in 1883 by the U.S. Post Office in order to correct the grammatical error to the masculine San Angelo. Today, San Angelo is a thriving community with a friendly spirit and resolve that reflects its pioneer heritage.