The area around Rio Grande City was first settled by Spanish colonists on the southern bank of the river as Camargo.

The area was strategic as the furthest point up the Rio Grande that was navigable and regularly accessible to the era's steamboats.

During the early stages of the war, US soldier Henry Clay Davis married Hilaria de la Garza Falcon, a resident of Camargo south of the river.

At the end of the war, Davis set out to organize this area into a formal city; he divided the land into plots to be sold.

In addition, because of its prominence and exploits by local residents, it was part of the romanticized concept in the United States of the "Wild West".

Famous early residents include Joshua H. Bean, brother of Judge Roy Bean, and the first mayor of San Diego, California; Orlando C. Phelps, one of the few surviving members of the Mier Expedition; Edwin R. Rainwater, hero of the Texas Revolution; Edward R. Hord, an influential early South Texas statesman; and John L. Haynes, a native Virginian politician and writer who was a strong proponent of Mexican-American (Tejano) rights and outspoken anti-secessionist before the Civil War.

La Borde was a French riverboat trader and merchant who commissioned the mansion's design in Paris.

He had this refined by architects in San Antonio, Texas, and oversaw construction of the building along Main Street.

[5] In the 1970s and into the 1980s, federal law enforcement officials concentrated their anti-drug smuggling efforts on Starr County.

[6] In spite of Rio Grande City's rich architectural heritage, many buildings in the old downtown district are abandoned, dilapidated, or crumbling.

[8] The fort was active until 1944 when the property was sold to the Rio Grande City public schools system.

These include the sentry and guard houses, barracks, officers quarters, bakery, hospital and post headquarters,[9] situated along Ringgold Avenue, Lee Circle, 12th Cavalry and F Troop streets.

The Rio Grande City United States Army Reserve Center is the only remaining military presence at the Fort Ringgold area.